Re: Mersenne: Factoring above 2^67

2004-02-12 Thread Richard Woods
Emrecan Dogan wrote: > One of my computers is assigned to run factoring tests > continuously. I saw that my that computer's last two results > were "no factor up to 2^67" . Then i checked the "cleared > exponents list" on the primenet webpage. There were no trace of > my exponents That's because t

Mersenne: Factoring above 2^67

2004-02-07 Thread Emrecan Dogan
Hi,   One of my computers is assigned to run factoring tests continuously. I saw that my that computer's last two results were "no factor up to 2^67" . Then i checked the "cleared exponents list" on the primenet webpage. There were no trace of my exponents but i saw many factored exponents with a f

Re: Mersenne: Factoring hiccup?

2003-02-14 Thread Mary K. Conner
At 10:49 PM 2/13/03 -0600, Steve Harris wrote: I can't tell you what is causing that, but I can tell you that it has happened to me as well. I have only noticed it on a machine which I switched to factoring because it consistently got errors during LL testing. With TF I get no errors, but do get

Re: Mersenne: Factoring hiccup?

2003-02-13 Thread Steve Harris
y six months. Regards, Steve -Original Message- From: Gordon Bower <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] <[EMAIL PROTECTED]> Date: Thursday, February 13, 2003 5:28 AM Subject: Mersenne: Factoring hiccup? > > >An odd thing happened today. I have version 21.4.1 on my

Mersenne: Factoring hiccup?

2003-02-13 Thread Gordon Bower
An odd thing happened today. I have version 21.4.1 on my laptop (a PIII-1000, but only turned on a few hours a day so that LL tests would take months) doing trial factoring. I ahppened to see the following in the screen display tonight: [Feb 13 01:44] Factoring M21632497 to 2^67 is 14.43% comple

Re: Mersenne: Factoring Top 100

2003-01-22 Thread Michael Kilfoyle
AH yes... I recall when I was up there at about 120 on LL maybe better. (Bnow someplace around 240 not sure i'll need to go look after this msg. (B Even with 12 or so systems it still slips... the PC's , like me, are (Bgetting old!!! On the factor side (slow old PC ) they just keep chewing (Ba

Re: Mersenne: Factoring Top 100

2003-01-21 Thread Mary K. Conner
At 12:07 AM 1/22/03 +, Russel Brooks wrote: Well I've recently reached my 2nd GIMPS goal of getting into the top 100 factoring. Last summer I made it to the top 1000 LL testers and then switched from double checks to factoring to make my mark there. Now what to try for? :-) Bah, top 100 f

RE: Mersenne: Factoring Top 100

2003-01-21 Thread Aaron
table does seem pretty close, relatively speaking... Aaron > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED]] On Behalf Of > Russel Brooks > Sent: Tuesday, January 21, 2003 4:07 PM > To: [EMAIL PROTECTED] > Subject: Mersenne: Factoring Top 100 &

Mersenne: Factoring Top 100

2003-01-21 Thread Russel Brooks
Well I've recently reached my 2nd GIMPS goal of getting into the (Btop 100 factoring. Last summer I made it to the top 1000 LL (Btesters and then switched from double checks to factoring to (Bmake my mark there. (B (BNow what to try for? :-) (B (BCheers... Russ (B (BDIGITAL FREEDOM! -->

Mersenne: Factoring bits

2002-02-12 Thread George Woltman
Hi, At 09:18 PM 2/12/2002 +0100, Achim Passauer wrote: >And for all other readers all(?) factors with more than 99 bits which are >part of the latest cleared exponents report: > >14308961 103 F 9394020965332917865679071542783 There are two minor shortcoming in the prime95 to primenet protocol

Mersenne: Factoring top 10

2002-02-12 Thread George Woltman
Hi, At 11:41 AM 2/12/2002 -0800, Aaron Blosser wrote: >PS - I'm just thrilled because I found a factor of an exponent that beat >my previous record... 101 bit factor. I'm too lazy to look through the >cleared exponents list, so does anyone know what the largest factor is >that has been found by

Mersenne: Factoring assignment ends early w/no factor

2002-01-10 Thread Mary Conner
I have a machine that was close to finishing its first factoring assigment. It was 94.5% complete on the last (to 65 bits) pass. I estimate the remainder would take about 3 to 4 hours to complete. I started up a kids program for my son, he played with it for about 15 minutes and then exited. I

Mersenne: Re: MERSENNE: Factoring Failure?

2001-10-03 Thread Eric Hahn
Steve Harris wrote: >-Original Message- >From: [EMAIL PROTECTED] <[EMAIL PROTECTED]> >To: [EMAIL PROTECTED] <[EMAIL PROTECTED]> >Date: Tuesday, October 02, 2001 3:44 PM >Subject: Re: FW: Mersenne: Re: Factoring Failure? > > >> > Either way, GIMPS >> > has never considered missing a factor

Mersenne: Factoring failure?

2001-09-30 Thread Daniel Swanson
Yesterday I was assigned M7027303 to doublecheck. The number came with the claim that it had no factors less than 62 bits. But my P-1 factorization of the number found this 55-bit factor: [Sun Sep 30 13:53:26 2001] P-1 found a factor in stage #1, B1=35000, B2=463750. UID: dswanson/nosnawsd, M70

Re: Mersenne: Factoring on a P4 - CORRECTION

2001-06-22 Thread Brian J. Beesley
--- Forwarded message follows --- From: "Brian J. Beesley" <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] Date sent: Fri, 22 Jun 2001 18:46:43 - Subject: Re: Mersenne: Factoring on a P4 Copies to:

Re: Mersenne: Factoring on a P4

2001-06-22 Thread Eric Hahn
Bradford J. Brown wrote: >For some reason, I am at a loss to explain, a v21 P4 1.4 GHz >factors significantely slower that a P3 v20 700MHz. Is there a >reason, and solution, for this? Hmmm... Good question... AFAIK, the only change George has or is going to make in the factoring code since v1

Re: Mersenne: Factoring on a P4

2001-06-22 Thread Michael Bell
> BTW there was an "unreasonable" acceleration of trial factoring > between the P5 architecture (Pentium Classic/MMX) and the P6 > architecture (Pentium Pro / PII / PIII / Celeron / Xeon), so you > can't simply assume that Intel doesn't care about integer > performance! But they clearly don't

Re: Mersenne: Factoring on a P4

2001-06-22 Thread Brian J. Beesley
On 22 Jun 2001, at 13:12, [EMAIL PROTECTED] wrote: > For some reason, I am at a loss to explain, a v21 P4 1.4 GHz factors > significantely slower that a P3 v20 700MHz. Is there a reason, and > solution, for this? Good question. AFAIK George has done nothing to the factoring code. You will see

Mersenne: Factoring on a P4

2001-06-22 Thread gsi26549
For some reason, I am at a loss to explain, a v21 P4 1.4 GHz factors significantely slower that a P3 v20 700MHz. Is there a reason, and solution, for this? Bradford J. Brown - This message was sent using GSWeb Mail Services. http://www.gasou.edu/gs

Mersenne: Factoring M727 through M(M727) revisited

2001-05-22 Thread Alexander Kruppa
Hi all, I think I found a (although purely theoretical) way to find a factor of M(p) by factoring M(M(p)). Ok here goes: f is a prime factor of M(M(p)), 2^(M(p)) = 1 (mod f) so the order of 2 in Z/f*Z is !=1, divides M(p) but is not neccessarily equal to M(p). Lets call it c. Since the order of

Re: Mersenne: Factoring on elderly machines.

2001-03-05 Thread Michael F. Yoder
On the subject of people with older machines despairing: on a Sun workstation my primitive-trinomial program takes about 10 hours (but depending on how many other engineers are using the machine) to test a q value for Richard Brent's distributed computing project. (It is to find primitive trinomi

Re: Mersenne: Factoring on elderly machines.

2001-03-04 Thread vincent mooney
At 06:05 AM 3/4/01 -0800, Paul Leyland wrote: >Three weeks ago, I wrote: > >> The integer factoring people can always use more cycles, and >> even antique machines make valuable contributions in a reasonable >> time. For instance, I have small number of DECstations and a Sun >> SS2 on my home ne

Mersenne: Factoring on elderly machines.

2001-03-04 Thread Paul Leyland
Three weeks ago, I wrote: > The integer factoring people can always use more cycles, and > even antique machines make valuable contributions in a reasonable > time. For instance, I have small number of DECstations and a Sun > SS2 on my home network all running the ECMNET client. These > boxes

Re: Mersenne: factoring the higher exponents

2000-12-16 Thread Brian J. Beesley
On 15 Dec 00, at 10:39, Henk Stokhorst wrote: > I spend the past months factoring the range 16.000.000 up to 17.000.000 > form 2^52 up to 2^58. I reported the results once a week, which are > included in the database. This week someone else started to work on this > as well although up to 2^56. T

Mersenne: factoring the higher exponents

2000-12-15 Thread Henk Stokhorst
L.S., I spend the past months factoring the range 16.000.000 up to 17.000.000 form 2^52 up to 2^58. I reported the results once a week, which are included in the database. This week someone else started to work on this as well although up to 2^56. This work is therefor done twice. What is being d

RE: Mersenne: Factoring

2000-12-01 Thread Paul Leyland
> The problem is for the government to factor the huge composite number > for each candidate afterwards. Can someone give me a rough > estimate of > how long it would take a good supercomputer to check an arbitrary > 100,000,000 digit number for several factors that are each a known 150 > digit

Re: Mersenne: Factoring

2000-12-01 Thread Nathan Russell
Paul Leyland wrote: > > > >We could let prime95 decide the next election . > > >Give everybody a different prime number. Multiply the primes for > > candidate A together, likewise for B. > > > > And like in this election, unless we can completely factor > > the results, > > we wouldn't know who

RE: Mersenne: Factoring

2000-12-01 Thread Paul Leyland
> >We could let prime95 decide the next election . > >Give everybody a different prime number. Multiply the primes for > candidate A together, likewise for B. > > And like in this election, unless we can completely factor > the results, > we wouldn't know who won, either. > > :) I note the

Re: Mersenne: Factoring

2000-11-30 Thread Peter-Lawrence . Montgomery
Chris Nash proposed: > >We could let prime95 decide the next election . > >Give everybody a different prime number. Multiply the primes for > candidate A together, likewise for B. > And like in this election, unless we can completely factor the results, > we wouldn't know who won, either

Re: Mersenne: Factoring

2000-11-30 Thread Chris Nash
Hi folks, Off-topic I know, but... >We could let prime95 decide the next election . >Give everybody a different prime number. Multiply the primes for candidate A together, likewise for B. And like in this election, unless we can completely factor the results, we wouldn't know who won, either.

Mersenne: Factoring

2000-11-30 Thread Frank_A_L_I_N_Y
We could let prime95 decide the next election . Give everybody a different prime number. Multiply the primes for candidate A together, likewise for B. If the factorization of the composite is not square free then we know that 1) Someone voted twice for the same candidate, and 2) We know w

Re: Mersenne: Factoring

2000-06-18 Thread Vincent J. Mooney Jr.
Thanks for the factor.exe citation. At 01:40 AM 6/16/00 -0700, Jim Howell wrote: >[Wed 14 Jun 2000, Paul Leyland writes] > >Today I found this number 3756482676803749223044867243823 with ECM and >B1=10,000. It has two factors, each of 16 digits, which could *not* have >been found by trial divisi

Mersenne: Factoring Assignments: Are They Always "First-Time?"

2000-06-18 Thread Will Edgington
Stefan Struiker writes: When a requested factoring assignment is listed with, say, 52 in an account log, does this mean it has been factored to 52 bits, but _without_ success? Yes, the number should have no factors less than 2^52. Or could a factor have already been found in some ca

RE: Mersenne: Factoring with ECM

2000-06-18 Thread Paul Leyland
> From: Yann Forget [mailto:[EMAIL PROTECTED]] > Could you explain this to me ? I can try. The text below is deliberately informal in style and far from mathematically rigorous. The mathematicians on the list will have to forgive me; those who want a more rigorous explanation should be able to

Re: Mersenne: Factoring Assignments: Are They Always "First-Time?"

2000-06-17 Thread Eric Hahn
Jeff Woods wrote: >>being found. Currently, all exponents thru Prime95's limit of >>79.3M have been factored to at least 2^50... If a factor is >>found for an exponent, it's eliminated from further testing >>of any kind. > >Isn't the factor itself verified? Yes, it is. However, at least in the

Re: Mersenne: Factoring Assignments: Are They Always "First-Time?"

2000-06-17 Thread Nathan Russell
>From: Jeff Woods <[EMAIL PROTECTED]> >To: [EMAIL PROTECTED] >Subject: Re: Mersenne: Factoring Assignments: Are They Always >"First-Time?" >Date: Sat, 17 Jun 2000 17:14:00 -0400 > >At 01:00 PM 6/17/00 -0700, you wrote: (snip) >>If a factor is &g

Re: Mersenne: Factoring Assignments: Are They Always "First-Time?"

2000-06-17 Thread Jeff Woods
At 01:00 PM 6/17/00 -0700, you wrote: >being found. Currently, all exponents thru Prime95's limit of >79.3M have been factored to at least 2^50... If a factor is >found for an exponent, it's eliminated from further testing >of any kind. Isn't the factor itself verified? ___

Re: Mersenne: Factoring Assignments: Are They Always "First-Time?"

2000-06-17 Thread Eric Hahn
Stefan Struiker wrote: >When a requested factoring assignment is listed with, say, 52 in >an account log, does this mean it has been factored to 52 bits, >but _without_ success? Or could a factor have already been >found in some cases, but less than 52 bits long? If it's listed as 52 in the fa

Mersenne: Factoring Assignments: Are They Always "First-Time?"

2000-06-17 Thread Stefan Struiker
TeamG: When a requested factoring assignment is listed with, say, 52 in an account log, does this mean it has been factored to 52 bits, but _without_ success? Or could a factor have already been found in some cases, but less than 52 bits long? My strategy in factoring 13.3 mill exponents and u

Mersenne: Factoring with ECM

2000-06-16 Thread Yann Forget
Hi, Could you explain this to me ? I am factoring Fermat numbers with ECM. Is this relevant in this case ? Thanks in advance, Yann > Paul Leyland said: As long as the coefficients of the curve and the starting point are recorded, we can re-run exactly the same computation, with the small primes

Mersenne: Factoring

2000-06-16 Thread Jim Howell
[Wed 14 Jun 2000, Paul Leyland writes] Today I found this number 3756482676803749223044867243823 with ECM andB1=10,000.  It has two factors, each of 16 digits, which could *not* havebeen found by trial division in any reasonable time.   -   I use a program called "factor.exe", whi

Mersenne: Factoring in the 60m range

2000-06-12 Thread gordon spence
This is a call to those people that I was mailing the results of trial factoring to, for numbers in the 60-69m range. To cut a long story short I have 'lost' your email addresses. If anyone else still wants this data, then please mail me off the list and I'll add you to the distribution list.

Re: Mersenne: factoring

2000-04-19 Thread Martijn Kruithof
Note that Mfactor (as currently configured) > doesn't support putting multiple exponents into a to-do > file, so the best way to trial factor lots of exponents > is probably just to paste the one-line inputs needed for > the exponents, one after another, into the same window - > when the program

Mersenne: factoring

2000-04-19 Thread EWMAYER
Brian Beesley (Mersenne Digest 715, 7. April) wrote: >There are also factoring programs available in portable >high-level-language source format, in particular look >for Mfactor.c If it wasn't for the fact that factoring >is so far ahead of LL testing, I'd probably switch my >Alpha system to fact

Re: Mersenne: Factoring Depths

2000-04-01 Thread Eric Hahn
Dave Mullen wrote: I'd just like to get a clarification on some files I downloaded from the Entropia FTP. Re the file of exponents, and how far they have been trial factored. I extracted a range using the decomp program. Each exponent has a number by the side, but I am unclear to what this

Mersenne: Factoring Depths

2000-03-31 Thread Dave Mullen
I'd just like to get a clarification on some files I downloaded from the Entropia FTP.   Re the file of exponents, and how far they have been trial factored.   I extracted a range using the decomp program. Each exponent has a number by the side, but I am unclear to what this number refers.

Re: Mersenne: Factoring beyond ECM

2000-01-23 Thread Hans-Martin Anger
<[EMAIL PROTECTED]> An: <[EMAIL PROTECTED]> Gesendet: Samstag, 22. Januar 2000 23:24 Betreff: Mersenne: Factoring beyond ECM > I'm interested in trying to factor composite numbers with 100 to 200 > digits. ECM becomes impractical for numbers without any factors below > 50 dig

Re: Mersenne: Factoring beyond ECM

2000-01-22 Thread Foghorn Leghorn
On Sun, 23 Jan 2000 02:06:26 +0100 (CET), you wrote: >MPQS is ok for numbers up to about 100 digits, at which time NFS takes >over. Is there a good implementation of this available online? >Have a look at Conrad Curry's NFSNET, > http://orca.st.usm.edu/~cwcurry/nfs/nfs.html> Foghorn Leghorn [E

Re: Mersenne: Factoring beyond ECM

2000-01-22 Thread Henrik Olsen
On Sat, 22 Jan 2000, Foghorn Leghorn wrote: > I'm interested in trying to factor composite numbers with 100 to 200 > digits. ECM becomes impractical for numbers without any factors below > 50 digits or so. I have heard of algorithms such as MPQS which are > used to tackle larger numbers. Are there

Mersenne: Factoring beyond ECM

2000-01-22 Thread Foghorn Leghorn
I'm interested in trying to factor composite numbers with 100 to 200 digits. ECM becomes impractical for numbers without any factors below 50 digits or so. I have heard of algorithms such as MPQS which are used to tackle larger numbers. Are there any (preferably free) implementations of this metho

Re: Mersenne: Factoring Mersenne

2000-01-22 Thread Will Edgington
Daniel Grace writes: > Anyway, any mersenne's factor can be written as 2kp+1 > directly). Call (P-1)/p = Q > > Then 2n = Q mod p > n = Q/2 mod p which is well defined > Therefore we can find the sun of the two factors mod p. I think what you are trying to say is M_p

Re: Mersenne: Factoring Mersenne

1999-11-25 Thread Daniel Grace
> Anyway, any mersenne's factor can be written as 2kp+1 > > directly). Call (P-1)/p = Q > > Then 2n = Q mod p > n = Q/2 mod p which is well defined > Therefore we can find the sun of the two factors mod p. I think what you are trying to say is M_p is composite for p a prime iff 1+2kp divides (

Mersenne: Factoring Mersenne

1999-11-24 Thread Chris Jefferson
Hello! I was fiddling around with Mersenne factors the other day and came across an interesting result. I'm not sure if it is of any use, but I think if anyone can extend it just a little further, then it would cut down the numbers we would have to try to factor by a HUGE amount... Anyway, any m

Re: Mersenne: Factoring 2^n+1 and 2^n-1

1999-11-03 Thread Brian J. Beesley
On 3 Nov 99, at 13:53, Alex Kruppa wrote: > Ernst Mayer once mentioned to me that Prime95 needs twice the FFT size for 2^n+1 >numbers (compared to 2^n+1 numbers). Does that mean that George is using the identity > 2^(2n)-1 = (2^n+1)(2^n-1) ? I was wondering why ECM on 2^n+1 numbers took much >l

Mersenne: Factoring 2^n+1 and 2^n-1

1999-11-03 Thread Alex Kruppa
Hi, Ernst Mayer once mentioned to me that Prime95 needs twice the FFT size for 2^n+1 numbers (compared to 2^n+1 numbers). Does that mean that George is using the identity 2^(2n)-1 = (2^n+1)(2^n-1) ? I was wondering why ECM on 2^n+1 numbers took much longer than on 2^n-1 of the same size.. That

RE: Mersenne: Factoring numbers...

1999-10-12 Thread Paul Leyland
> Anyway, still waiting to hear if ECM will, > eventually, find all factors or if it leaves "factors" in the range... The best way of thinking about this is that each curve at a given bound has a small but non-zero probability of finding a factor of a certain length, assuming that one exists. Th

Re: Mersenne: Factoring numbers...

1999-10-12 Thread Eric Hahn
Jukka Santala wrote: >Is it just me, or does factoring smaller Mersenne numbers take >propotionally much longer? I would expect M727 to be much faster >than the 33M range to a fixed depth, yet the opposite _seems_ to >be true. For any given factoring bit-depth, larger exponents will take a shorte

Re: Mersenne: Factoring numbers...

1999-10-12 Thread Jukka Santala
"Brian J. Beesley" wrote: // Regarding factoring Mersennes to v19 depth... > If you do decide to do this, you're on your own - don't be surprised > if someone else does the same thing independently - there's no > mechanism for coordination to avoid wasted effort. Partially. There now exists soft

Re: Mersenne: Factoring numbers...

1999-10-12 Thread Jukka Santala
George Woltman wrote: > Since factors are of the form 2kp+1 there are many more factors to test > when you factoring M727. Yes each factor can be tested in less time, > but this is overwhelmed by extra factors to test. Thanks to everybody pointing this one out, I missed the obivious implication

Re: Mersenne: Factoring numbers...

1999-10-12 Thread Brian J. Beesley
On 12 Oct 99, at 15:30, Jukka Santala wrote: > Is it just me, or does factoring smaller Mersenne numbers take > propotionally much longer? I would expect M727 to be much faster than > the 33M range to a fixed depth, yet the opposite _seems_ to be true. Yes, it _does_ take _much_ longer. The tim

Re: Mersenne: Factoring numbers...

1999-10-12 Thread George Woltman
Hi, At 03:30 PM 10/12/99 +0300, Jukka Santala wrote: >Is it just me, or does factoring smaller Mersenne numbers take >propotionally much longer? I would expect M727 to be much faster than >the 33M range to a fixed depth, yet the opposite _seems_ to be true. Since factors are of the form 2kp+1 th

Re: Mersenne: Factoring numbers...

1999-10-12 Thread Henrik Olsen
On Tue, 12 Oct 1999, Jukka Santala wrote: > Is it just me, or does factoring smaller Mersenne numbers take > propotionally much longer? I would expect M727 to be much faster than > the 33M range to a fixed depth, yet the opposite _seems_ to be true. It's not just you, it's a natural consequence of

Mersenne: Factoring numbers...

1999-10-12 Thread Jukka Santala
Is it just me, or does factoring smaller Mersenne numbers take propotionally much longer? I would expect M727 to be much faster than the 33M range to a fixed depth, yet the opposite _seems_ to be true. Ofcourse, I can't be sure about this, because the real complaint I have is that factoring numbe

Mersenne: Factoring data

1999-10-02 Thread George Woltman
Hi all, At several users request I've uploaded factoring data for all exponents below 79,300,000. You'll need a special decompression program I wrote. See http://www.mersenne.org/status.htm for details. Regards, George _ Unsubscri

Re: Mersenne: Factoring

1999-09-21 Thread Jud McCranie
At 04:27 PM 9/21/99 -0700, Eric Hahn wrote: We know that any factor of 2^p-1 is in the form 2kp+1. >Letting x >=2, > Can (2kp+1)^x = 2^p-1 ?? > Can (2kp+1)^x * (2kp+1) ... = 2^p-1 ?? No known factors of Mersenne numbers have x>1, but it hasn't been proven that it is impossible. +-

Mersenne: Factoring

1999-09-21 Thread Eric Hahn
Does anybody know if there is an exponent where the factor is, or know whether there is a proof on whether a factor can (or can't) be, a root?? A square?? To clarify this: We know that any factor of 2^p-1 is in the form 2kp+1. Letting x >=2, Can (2kp+1)^x = 2^p-1 ?? Can (2kp+1)^x * (2kp

Re: Mersenne: Factoring & LL tests

1999-07-18 Thread Pierre Abbat
On Sun, 18 Jul 1999, Geoffrey Faivre-Malloy wrote: > I was reading Fermat's Enigma today and something occurred to me...would it > be possible to work with a number quicker if we used a higher base? I.E. > Use base 32 instead of base 10? Thus, you're doing less math. Of course, > this would hav

Re: Mersenne: Factoring & LL tests

1999-07-18 Thread Jud McCranie
At 01:10 PM 7/18/99 -0400, Geoffrey Faivre-Malloy wrote: >I was reading Fermat's Enigma today and something occurred to me...would it >be possible to work with a number quicker if we used a higher base? I.E. >Use base 32 instead of base 10? Multiple precision arithmetic operations do that. +-

Mersenne: Factoring & LL tests

1999-07-18 Thread Geoffrey Faivre-Malloy
I was reading Fermat's Enigma today and something occurred to me...would it be possible to work with a number quicker if we used a higher base? I.E. Use base 32 instead of base 10? Thus, you're doing less math. Of course, this would have to be in software because the floats can't be in that bas

re: Mersenne: Factoring and Databases

1999-06-26 Thread Lucas Wiman
> Why test factor for primes in the range 2^1 to 2^10? If someone made the > table I described, it is possible that all primes less than 2^10 are in the > table I have described because they are known divisors of a Mersenne number > OR are not candidates for dividing any Mersenne number by other

Mersenne: Factoring and Databases

1999-06-26 Thread Vincent J. Mooney Jr.
I may be a little obtuse here (and spelling, expression of ideas may be inadequate) but A Mersenne number's prime divisors are unique to that number. Letting a and b be primes, 2^a - 1 and 2^b - 1 have completely different factors. So we can make a table (database) with p1 divides M(q1) p2

Mersenne: Factoring, again

1999-06-20 Thread Anonymous
Brian J. Beesley writes: I put a development version on my anon ftp server about three days ago. ftp://lettuce.edsc.ulst.ac.uk/gimps/DecaMega/factor95.c Um, that's an unfortunate choice of name; George's P-1 factorer is "Factor95" (though there's a newer version, renamed to Factor98). O

Mersenne: Factoring, again

1999-06-20 Thread Anonymous
> Will change the "engine" to keep going to 2^33 after finding the > first factor & report the results from that. OK, here's the results. (All factors to 2^33 found, input is 159,975 largest primes < 36 million) Sieve 6 smallest primes, 3517525 calls, 40.15s Sieve 10 smallest primes, 2972446 c

Mersenne: Factoring, again

1999-06-20 Thread Anonymous
> That does sound like it's faster, but let me go thru some numbers. I > don't recall exactly, but I'm sure my earlier run took less than 72 > hours; 72 hours divided by 20 seconds is 72*3600/20 = 12960. Brian > stopped at 2^32 and I went to at least 2^33 for a factor of two; > 12960/2 = 6480.

Mersenne: Factoring and M38

1999-06-19 Thread Anonymous
Well, looks like factoring on TI calculators won't be feasible or useful. :-( Before more data comes in, I'd like to state that I believe three things: A) The 38th Mersenne prime discovered has an exponent in the neighborhood of 6,900,000. B) We *are* missing a Mersenne prime between 3021377 and

Re: Mersenne: Factoring

1999-06-15 Thread Anonymous
> Now, this implies that for no 0http://www.scruz.net/~luke/signup.htm

Re: Mersenne: Factoring

1999-06-15 Thread Anonymous
Chris Jefferson <[EMAIL PROTECTED]> writes: > Just one question / comment. > > We want to find 2^p mod n where n is in form 2kp + 1 > If we KNOW 2kp + 1 is prime, then the euler totient fn. of n is 2kp, call > this T > > Also, if a is co-prime to n, a^T=1 mod n > 2 is obviously co-prime to n, s

Re: Mersenne: Factoring

1999-06-15 Thread Anonymous
Hmm... Thanks for all the advice on factoring! Just one question / comment. We want to find 2^p mod n where n is in form 2kp + 1 If we KNOW 2kp + 1 is prime, then the euler totient fn. of n is 2kp, call this T Also, if a is co-prime to n, a^T=1 mod n 2 is obviously co-prime to n, so 2^T=1 mod n

Re: Mersenne: factoring 10^7 digits

1999-06-14 Thread lrwiman
>> Sounds about right for a SWAG estimate. > SWAG? SWAG stands for Scientific Wild-Assed Guess - translation: educated guess -Lucas Wiman Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm

Re: Mersenne: Factoring

1999-06-14 Thread lrwiman
> I was just wondering, could anyone give me any info on how factoring is > done, is there a preliminary factoring before numbers send out, how high > we factor, what possible factors are, etc. and also, I would really like > to see the maths behind it as well. I need something to study over summm

Mersenne: Factoring

1999-06-14 Thread Chris Jefferson
I was just wondering, could anyone give me any info on how factoring is done, is there a preliminary factoring before numbers send out, how high we factor, what possible factors are, etc. and also, I would really like to see the maths behind it as well. I need something to study over summmer vac :

Re: Mersenne: Factoring Mersenne numbers

1999-05-27 Thread lrwiman
>I was thinking (always dangerous!) about some of the smaller >Mersenne numbers, like 2^727-1, for which no factors are known. >2^727-1 has 219 digits, and we are pretty darn sure that it has no >prime factors less than 40 digits long. Therefore it would seem >sensible to "assume" that it is the p

Re: Mersenne: Factoring Mersenne numbers

1999-05-27 Thread Jud McCranie
At 02:48 PM 5/27/99 +, [EMAIL PROTECTED] wrote: >>which it looks "feasible" to solve - yielding directly the two prime >>factors of 2^n-1, assuming the assumption is correct. > >Aaargh! The correct rearrangement is > >2 * a * b * n^2 + (a + b) * n - (2^(n - 1) - 1) = 0 > >Doesn't affect the a

Re: Mersenne: Factoring Mersenne numbers

1999-05-27 Thread BJ . Beesley
Earlier today I wrote: > >In this case, there exist (large prime) integers a, b such that >(2 * a * n + 1) * (2 * b * n + 1) = 2^n - 1 > >A bit of rearrangement leads to the equation > >2 * a * b * n^2 + (a + b) * n - 2^(n - 1) = 0 > >which it looks "feasible" to solve - yielding directly the two

Mersenne: Factoring Mersenne numbers

1999-05-27 Thread Brian J Beesley
Sorry if this has been mentioned before, but... I was thinking (always dangerous!) about some of the smaller Mersenne numbers, like 2^727-1, for which no factors are known. 2^727-1 has 219 digits, and we are pretty darn sure that it has no prime factors less than 40 digits long. Therefore it w

Re: Mersenne: Factoring bignums

1999-05-13 Thread Henrik Olsen
On Wed, 12 May 1999, Pierre Abbat wrote: > Is there a program for factoring numbers up to, say, 2^128 in a reasonable > time? I tried bc but it doesn't have a factor command, so I wrote a loop and it > spent all its time outputting. Get Richard Crandall's giantint package, it contains factor, whic

Mersenne: Factoring bignums

1999-05-12 Thread Pierre Abbat
Is there a program for factoring numbers up to, say, 2^128 in a reasonable time? I tried bc but it doesn't have a factor command, so I wrote a loop and it spent all its time outputting. phma Unsubscribe & list info -- http://www.scr

Mersenne: factoring and LL-testing with perl

1999-04-14 Thread Robert Friberg
Hi all, I haven't run prime95 the past year and I'm still among the top ten producers. Well, last time I checked I was. Didn't think I would last that long up there. ;-) I was goofing around with perl today and recalled a cool way of factoring/primality checking using patternmatching. I also t

Mersenne: Factoring & bugs

1999-04-08 Thread Will Edgington
[EMAIL PROTECTED] writes: As LL tests begin to go beyond the limits of older machines, now may be a good time to consider a distributed factoring effort. I've wanted to see one for a while now but frankly, implementing many of the algorithms is over my head. That, and the lack of a p

Mersenne: Factoring

1999-04-02 Thread poke
Do I need to upgrade if I am only factoring? -- ~~~ : WWW: http://www.silverlink.net/poke : Boycott Microsoft : : E-Mail: [EMAIL PROTECTED] : http://www.vcnet.com/bms: ~

Re: Mersenne: Factoring on a 486SX

1999-02-20 Thread Bryan Fullerton
On Sat, Feb 20, 1999 at 12:17:58PM -0500, Marc Getty <[EMAIL PROTECTED]> wrote: > > The "487 math co-processer" is actually a 486DX chip. Unlike previous > Intel CPUs where you just add an external math co-processer, the 486 > SX line was an afterthought. Actually, 486sx's were 486dx's that didn

Mersenne: Factoring on a 486SX

1999-02-20 Thread Marc Getty
> I'm running PrimeNet on my 486sx/25 Linux router box (yeah, I know...). Right > now it's factoring M8956237, and it seems to do about one pass per day. It's > going to take a while. :) > Would adding a 487 math co-processor speed this up? If so, by how much? I > have no idea about the algory

Mersenne: Factoring...

1999-02-19 Thread Bryan Fullerton
Howdy, I'm running PrimeNet on my 486sx/25 Linux router box (yeah, I know...). Right now it's factoring M8956237, and it seems to do about one pass per day. It's going to take a while. :) Would adding a 487 math co-processor speed this up? If so, by how much? I have no idea about the algoryt

Mersenne: Factoring

1999-02-15 Thread Will Edgington
Sander Hoogendoorn writes: Last weekend when i was testing Prime 95 i noticed that factoring low numbers took much longer as high numbers. Factoring M17XXX from 2^52 to 2^54 took minutes per pass while factoring M9XX from 2^52 to 2^54 took about one minute to complete the whol

Re: Mersenne: Factoring

1999-02-15 Thread Peter-Lawrence . Montgomery
"Sander Hoogendoorn" <[EMAIL PROTECTED]> asks > Last weekend when i was testing Prime 95 i noticed that factoring low > numbers took much longer as high numbers. > Factoring M17XXX from 2^52 to 2^54 took minutes per pass while factoring > M9XX from 2^52 to 2^54 took about one minute to comp

Mersenne: Factoring

1999-02-15 Thread Sander Hoogendoorn
Hi, Last weekend when i was testing Prime 95 i noticed that factoring low numbers took much longer as high numbers. Factoring M17XXX from 2^52 to 2^54 took minutes per pass while factoring M9XX from 2^52 to 2^54 took about one minute to complete the whole factoring. How is this possible?

Mersenne: Factoring Fermat Numbers

1999-01-30 Thread Alan Powell
At 12:14 AM 1/30/99 -0600, [EMAIL PROTECTED] wrote: > >More recently, I downloaded the source code from Perfectly Scientific >Inc (link is on the same page as above). I have compiled the source code >successfully, but the resulting program does not seem to be working, since I have >found none of

Mersenne: Factoring Fermat numbers

1999-01-30 Thread jrhowell
Sorry if this is a duplicate message. I am not sure if my previous attempt to send this message got there or not. Several months ago I downloaded fermat.exe from the Mersenne.org site ("zip file" at http://www.mersenne.org/fermat.htm). This program attempts to find factors of Fermat numbers (F1

Re: Mersenne: Factoring

1999-01-12 Thread Jud McCranie
At 08:30 AM 1/12/99 -0500, Alexey Guzeev wrote: > > Ok, George's programs looks for only for factors of M(n) in form >1) 2kn+1 > that's clear why >2) 1,7,17,23,31,41,47,49,71,73,79,89,97,103,113,or 119 modulo 120 > but this is not. Why factors 120k+13 are not considered? Or 120k+19? Why >only

Re: Mersenne: Factoring

1999-01-12 Thread Chris Nash
Alexey > Ok, George's programs looks for only for factors of M(n) in form >1) 2kn+1 > that's clear why >2) 1,7,17,23,31,41,47,49,71,73,79,89,97,103,113,or 119 modulo 120 > but this is not. Why factors 120k+13 are not considered? Or 120k+19? Why only those 16 reminders of >~30 primes below 120?

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