Re: Mersenne: Smallest unfactored composite (was types of work to request...)

1999-10-16 Thread Greg Hewgill

On Fri, Oct 15, 1999 at 01:03:57AM -0800, Gordon Bower wrote:
 PS - On an unrelated note --- what is the smallest natural number that is
 not known whether it is prime or composite? Surely *someone* out there is
 trying to work from the bottom up and factor every number. (I don't know
 the answer. I am guessing the it is a smallish number of maybe 15 or
 so decimal digits?)

Suppose you were keeping such a list. With one bit (prime vs not-prime) to
represent each number up to 10^15, you would need approximately 10^14 bytes of
storage, which is on the order of 100 terabytes. That would be your first
problem. The second problem would be if you were to present me with the
smallest number that was not factored, I could almost immediately present you
with a factorization (or show that it's prime).

The point is there are so many numbers, it would take far too much time to
determine the character of even the small ones that could individually be
characterized almost immediately.

Here's another argument - suppose the largest unfactored composite was C. How
long did it take to determine the factorization (or primality) of C-2? (C-1
would be even.) Then to factor C would only take a marginally longer amount of
time than it took for C-2. There is no reason you could not complete the
factorization of C.

Greg Hewgill
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Re: Mersenne: Smallest unfactored composite (was types of work to request...)

1999-10-16 Thread Peter-Lawrence . Montgomery

On Fri, Oct 15, 1999 at 01:03:57AM -0800, Gordon Bower wrote:
 Here's another argument - suppose the largest unfactored composite was C. How
 long did it take to determine the factorization (or primality) of C-2? (C-1
 would be even.) Then to factor C would only take a marginally longer amount of
 time than it took for C-2. There is no reason you could not complete the
 factorization of C.

Alas, if Gordon's argument is valid, then every positive integer would be
factored.  This is the principle of mathematical induction.

A computer may be in a loop.  It has factored C-2 and C-1, and is now
working on C.  The task of factoring C may indeed take only marginally longer 
than it took for C-2, but the extra time is nonetheless positive.
The next number may be factored as you read this paragraph,
so a journal article saying "Every number below this C has been factored, 
but C itself has not been" would become outdated almost 
immediately, even if true when submitted. 

We can use the same argument on how much water our bodies will hold, 
or how much pollution to allow.  At any given time, adding a single
molecule may seem safe.  But the capacities are finite.



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Re: Mersenne: Re: splitting up 10m digit primes

1999-10-16 Thread Chris Jefferson

On Sat, 16 Oct 1999, Jukka Santala wrote:

 "Brian J. Beesley" wrote:
 
  On 14 Oct 99, at 18:15, Chris Jefferson wrote:
  Surely this isn't really an issue. PrimeNet would surely recognise a
  result submitted by a "poacher" as such  either disqualify it
  automatically, or credit the actual owner of the assignment instead
  of the "poacher".
 
 Except that PrimeNet doesn't control the prize. This is the error everybody is doing.
 EFF is adminstrating the competition and prize, given by anonymous donaters to
 advance distributed computing / mathemathical algorithms on computers. PrimeNet is
 just one of the organizations (With largest changes known!) to get that prize, but it
 doesn't decide upon who gets it. The first person to present a prime filling the
 requirements will - and that's why result-files "few iterations short" will be worth
 more than their weight in gold.
 

Yes, but the licence for Prim95/NT specifies that anyone who uses this
program must obey it's licence. Someone using a partly completed file
would also be liable under this. However, proving that they has used the
interim file generated by this particular program might be difficult...



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Re: Mersenne: Re: splitting up 10m digit primes

1999-10-16 Thread Brian J. Beesley

On 16 Oct 99, at 7:35, Jukka Santala wrote:

 [ ... snip ... ]
 Except that PrimeNet doesn't control the prize. This is the error everybody is doing.
 EFF is adminstrating the competition and prize, given by anonymous donaters to
 advance distributed computing / mathemathical algorithms on computers. PrimeNet is
 just one of the organizations (With largest changes known!) to get that prize, but it
 doesn't decide upon who gets it. The first person to present a prime filling the
 requirements will - and that's why result-files "few iterations short" will be worth
 more than their weight in gold.

I think, if someone tried to pull this particular stunt, PrimeNet 
could inform EFF of the claimant's theft of the right to the 
discovery (which is what it amounts to). Another unfortunate example 
of the way in which large ca$h prizes can lead to unpleasantries, I'm 
afraid.
 
 You said... about making the repository write-only. And you seem to completely miss
 the point; the discussion here has centered around how to solve the problem that
 PrimeNet doesn't have the bandwidth or storage space to backup the intermediary
 files! So my suggestion was "distributed storage". This will solve the backup
 problem, but yes the above-mentioned prize-claim and double-check problem remains.
 Unfortunately, I think in that respect we're stuck.

Well, I sort of _did_ miss that particular point. But I have a 
solution. If you have a distributed filestore, controlled by a number 
of different people, then you encrypt  hack up the file you're 
saving and scatter pieces amongst the remote filestores. If you (the 
assignment owner) use a method based on a key otherwise known only to 
PrimeNet to scramble  scatter the file, the small chunk of data 
stored on any other individual's system is useless to them for the 
purposes of hijacking your work.

I think PrimeNet should know users' keys so that data can be 
recovered in the event of the user defaulting or accidentally 
destroying their own key (so that work done isn't lost). Presumably 
we trust the people running PrimeNet!

An obvious extension to this idea is to use a RAID type technique 
e.g. if you store each bit of a byte on a seperate host, so that the 
file is scattered over 8 hosts, you could send the parity bit to a 
ninth host. Then the distributed filestore is immune to loss of one 
of its hosts (by reason of network failure or unsecured loss of its 
filestore).

As for bandwidth and total filestore space needed - the first is, and 
will probably remain for some time, a problem, at least for most home 
users. 10,000 x 8 Mbyte save files is a lot of data by today's 
standards; nevertheless, 4 20GB drives at $200 each would just about 
cover it. (A random dip into a UK magazine shows Samsung 20.3GB 
UDMA66 IDE at £144 (sterling) each, so US$10 per GB should be 
achievable)


Regards
Brian Beesley
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Re: Mersenne: Islands of Truth

1999-10-16 Thread Darxus

On Fri, 15 Oct 1999, Jud McCranie wrote:

 At 05:45 PM 10/15/99 -0400, you wrote:
 
 I've put a graph of these "pairs" up on my web page.
 
 You can't really tell much from that graph - most of the points are hugging 
 the x-axis.

Most of those are pretty random... like, the higher your numbers get, the
more grouped they are.  

I have more thoughts on this, from reading
http://www.utm.edu/research/primes/notes/faq/NextMersenne.html
a few times, but I gotta get going.
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Re: Mersenne: The Mysterious Ways of S.T.L.

1999-10-16 Thread Jukka Santala

"Brian J. Beesley" wrote:

 They will, and they're very likely to be artificial.

Umm. I'm moderately familiar with statistics, that's actually part of why I'm not
looking for significance in the patterns. (For one thing, the wole concept of
statistics kinda excludes the possibility of using it to "find the right one", like
some people seem to be assuming they can do. Kinda like the various countries hosting a
celebration for the birth of the 6 billionth person on Earth;) However, I was
suggesting to those actually looking for patterns in there not to automatically assume
they need to work with the set of all Mersenne exponents vs. exponents of prime
Mersennes. For one thing, this will very rarely yield a result that is even a candidate
(As some have found out). On the other hand, this could be a way to check the working
of the conjencture... We can artificially generate this situation, thouhg. However,
small correction: With Mersennes, the Mersenne numbers size is directly propotional to
the exponent or number of bits in the number, so obiviously there's not much sense in
testing the two separately ;)

 -Donwulff

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Re: Mersenne: Islands of Truth

1999-10-16 Thread Darxus

On Fri, 15 Oct 1999, John R Pierce wrote:

  Darxus wrote:
 
   I've put a graph of these "pairs" up on my web page.
   http://www.op.net/~darxus/p_pairs.bmp
 
  Never use BMP on the WWW, please!
  There's no way for me to look at that.

Interesting, what browser are you using ?

 here, I whacked it for you...
 http://hogranch.com/files/Bitmaps/p_pairs.gif
 
 since it was a very-few color chart, GIF was the logical format.  BMP was
 71k. GIF is 4K.  nuff said?

I do not like .bmp because of microsoft and the fact that Jukka can't view
it (whatever the reason is).

I do not like .gif because of the copyright/patent thing on its
compression.

As far as I'm concerned, that only leaves .png, who's support is lacking.

Unfortunately, at this moment, I do not have the ability to do any
conversions, so thank you for putting up a .gif.

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Re: Mersenne: Islands of Truth

1999-10-16 Thread Darxus

On Sat, 16 Oct 1999, Darxus wrote:

 On Fri, 15 Oct 1999, Jud McCranie wrote:
 
  At 05:45 PM 10/15/99 -0400, you wrote:
  
  I've put a graph of these "pairs" up on my web page.
  
  You can't really tell much from that graph - most of the points are hugging 
  the x-axis.
 
 Most of those are pretty random... like, the higher your numbers get, the
 more grouped they are.  
 
 I have more thoughts on this, from reading
 http://www.utm.edu/research/primes/notes/faq/NextMersenne.html
 a few times, but I gotta get going.

Okay, that page is a bit overwhelming for me, but it looks like it's
saying that, when you graph log(log(p)) vs. n, where the logs are base 2,
p is part of 2^p-1, and n is the number of the mersenne prime (did I say
that right?), you'll get an approximation of a straight line.  All
mersenne primes will fit that pattern, but they are less likely to be *on*
the line than they are to be *near* the line.

Geez, I'm having difficulty putting this into words.

Like... primes are not likely to fall extreemly close to the line,
but they're probably going to be near it -- like, they're magnetically
repelled from the line.  This would cause random clumping.  

It would also cause random clumping when you graph P vs. N (where P is
part of 2^P-1, and N is the number of the merseene prime).  

I have no idea what would cause this, but if it's correct, we should be
able to calculate the probability of the distance from the line (if you're
doing the log log thing, or if you're fitting an exponential curve), and
predict more accurately where a prime would fall (you'd be predicting 2
points, one on either side of the line).


Gonna go regression test (proper term?) the extrapolations I've been
playing with assuming the distribution is totally random but approximating
an exponential curve
 
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Mersenne Digest V1 #645

1999-10-16 Thread Mersenne Digest


Mersenne Digest   Saturday, October 16 1999   Volume 01 : Number 645




--

Date: Fri, 15 Oct 1999 20:03:02 +0100
From: "Brian J. Beesley" [EMAIL PROTECTED]
Subject: Re: Mersenne: Modular arthimatic..

On 15 Oct 99, at 18:25, Chris Jefferson wrote:

 Just something I was pondering a couple of days ago...
 
 Consider a general number (odd) number c which can be factored into ab=c
 
 W.L.O.G. assume b is greater than a
 
 then let x=(a+b)/2 , y=(b-a)/2
 
 then (x+y)(x-y)=c
 
 x^2 - y^2 = c
 
 x^2 = c + y^2
 
 So if we can find if this equation has any integer solutions, we've found
 our factors...
 
 Ways of doing this:
 
 The difference of two squares is always an arthimetic progression of odd
 numbers. Here is an example..
 
 2^2 - 1^2 = 3
 3^2 - 2^2 = 5
 4^2 - 3^2 = 7
 
 and so on... So look at general sum of an arthimetic series
 
 S(n) = (n/2)(2a + (n-1)d) In this case d=2 and a is odd, so need to try to
 solve c = na + n(n-1)/2 for integers n,a
 
 Also, try to solve x^2 - y^2 = 0 mod c

Are we not back to Fermat's Method for factorization (again)?

If we're dead lucky and pick a value c such that a and b are very 
similar in magnitude, this method works a treat (hence it's very 
unwise to pick a public key which factorizes into two nearly equal 
numbers. You make the job of cracking your key a lot harder if you 
pick the product of two numbers which differ in length by a couple of 
bits.)

There is still a gap between the largest factors which can be found 
(practically, not theoretically) by techniques suited to "small" 
factors, like trial factoring, P-1 and even ECM, and Fermat's Method 
which is practical only for "small" values of b-a. (Fermat is just 
plain _awful_ at factorizing 3*p for large prime p!) Probably the 
continued fractions method is the best line of attack on numbers 
which resist "reasonable" efforts with other methods.

Regards
Brian Beesley
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--

Date: Fri, 15 Oct 1999 21:34:02 +0200
From: "Steinar H. Gunderson" [EMAIL PROTECTED]
Subject: Mersenne: Re: splitting up 10m digit primes

On Thu, Oct 14, 1999 at 06:15:52PM +0100, Chris Jefferson wrote:
In my personal opinion, the best way of doing this would be to set up 3
computers in a 'loop' all doing the same exponent. Then they could
communicate at regular intervals.

We are already doing this manually, although only with 2 computers (if
the residues match, you don't need the 3rd one). We're taking residues
every one million iterations, and mail them to each other. So far, they've
matched :-)

And if one machine is faster than the other -- well, then it goes on to
another exponent. No waiting needed.

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--

Date: Fri, 15 Oct 1999 17:10:58 EDT
From: [EMAIL PROTECTED]
Subject: Mersenne: The Mysterious Ways of S.T.L.

Hello, everybody. As usual I'm quoting different people. Disturbingly, I 
noticed a weird HTML tag on my last E-mail. I can assure you I didn't put it 
there, and don't know why my software's acting up on me (because I've never 
seen that jibberish before). HTML mail is evil, only second to MIME. Long 
live ASCII! Please excuse my delay in sending this message.

Also, if this extrapolation of the number of digits is accurate, there is 
another prime between the 37th  38th(p=6972593) discovered primes. 
Unfortunately, the extrapolation of P just didn't go well.  Actually, the 
extrapolated 39th mersenne prime is 6.34% off of 2^6972593-2.  I suppose 
that's not so bad.  That would also mean one was skipped. So it is currently 
my fairly strong opinion that a mersenne prime was skipped between the 37th  
38th discovered primes.  I reserve the right to change my mind at any 
instant. I'd also guess that the skipped prime may have been pretty close to 
2^5014947-1, and have a number of digits close to 1408773.

This is similar to the conjecture I made oh-so-long ago. 6.9M was confirmed, 
but at the same time I had to predict a missing one (which I said was 
probably in the 4M range, but that's far less certain). 

[EMAIL PROTECTED]: I'm really looking forward to hearing how you made your
estimates.
 How did you make this estimate ?  Fit an exponential curve to the known 
primes, and extrapolate the 1st one that should have at least 1m digits?
Who knows the mysterious ways of STL?

I usually just go by S.T.L. (my initials). 

At some point I had a vague recollection that STL had believed there was a
number missing, and I was quite happy to see that 

Re: Mersenne: problem with prme95 - spl file - ME TOO !

1999-10-16 Thread Michael Oates

Brian,

This will probably make you laugh, if it does don't tell me, I was not
ammused when I found out what had happened, read on...


On 15 Oct 99, at 13:16, Michael Oates wrote:

 I am also having the same problem, but only on one machine, I have 9 others
 that are fine, all are using the same version of v19 beta 4

What's different? Must be _something_ ...

I have been running Prime95 on this machine for about 4 weeks. It is on a
LAN with other machines also running Prime95.

I have a shortcut to run the program in the Startup folder.

Today I realised that not only was the server not being updated, but the
save files had not been altered for over a week. This was very odd as the
program was re-starting correctly where it left off. So I thought, it must
be storing the save file somewhere else. Then I also noticed that some of
the setting details were wrong, not just wrong, but were for a different
machine. I ran the program from the directory with File Explorer and it used
a different exponent and was at a different stage ! Eh !!!

I checked the shortcut that was in the Startup folder... well would you
believe it... it was pointing to another machine.

Some how Windows95 had changed the path to the shortcut all on it's own, and
had been running another exponent on another machine over the network. And
for some odd reason the details stored in local.ini were taken from the
local machine and the details from prime.ini were from the remote.

Now I know what you are probably thinking, it was not Windows95 that changed
the path, and that I made a mistake when I set it up... WRONG, very wrong. I
have seen this before... if you have a shortcut to a file, and remove the
file, and replace it with another one Windows95 inserts another path in any
shortcut to that program, this has cause no end of problems in the past.

This probably happend when I upgraded Prime95 with a newer verion, I moved
the directory else where by mistake, instead of copying it to make a backup.
I of course just copied it back again straight away, then copied the new
updated program to it... from... wait for it... the machine that the new
shortcut was pointing to. So somehow windows changed the shortcut path to
the directory on the remote machine, great eh !

All is now working ok, but I have lost over a weeks LL testing because of
it. No harm seems to have been done to the remote machine.

Regards,

Mike,

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Re: Mersenne: problem with prme95 - spl file - ME TOO !

1999-10-16 Thread Henrik Olsen

On Sat, 16 Oct 1999, Michael Oates wrote:
 I have been running Prime95 on this machine for about 4 weeks. It is on a
 LAN with other machines also running Prime95.
 
 I have a shortcut to run the program in the Startup folder.
For Windows 95 and prime95, this is the wrong approach, since as the
included story shows, this makes you vulnerable to the mangling of
shortcuts that Windows loves and we hate.
Instead, remove the shortcut from the startup folder, start
prime95 manually, choose "Options" and make sure "Windows 98/95 Service"
is checked, then it will start automagically, this is especially
important in networked setups, as the service runs even when noone's
logged in.

 Today I realised that not only was the server not being updated, but the
 save files had not been altered for over a week. This was very odd as the
 program was re-starting correctly where it left off. So I thought, it must
 be storing the save file somewhere else. Then I also noticed that some of
 the setting details were wrong, not just wrong, but were for a different
 machine. I ran the program from the directory with File Explorer and it used
 a different exponent and was at a different stage ! Eh !!!
 
 I checked the shortcut that was in the Startup folder... well would you
 believe it... it was pointing to another machine.
 
 Some how Windows95 had changed the path to the shortcut all on it's own, and
 had been running another exponent on another machine over the network. And
 for some odd reason the details stored in local.ini were taken from the
 local machine and the details from prime.ini were from the remote.
 
 Now I know what you are probably thinking, it was not Windows95 that changed
 the path, and that I made a mistake when I set it up... WRONG, very wrong. I
 have seen this before... if you have a shortcut to a file, and remove the
 file, and replace it with another one Windows95 inserts another path in any
 shortcut to that program, this has cause no end of problems in the past.
 
 This probably happend when I upgraded Prime95 with a newer verion, I moved
 the directory else where by mistake, instead of copying it to make a backup.
 I of course just copied it back again straight away, then copied the new
 updated program to it... from... wait for it... the machine that the new
 shortcut was pointing to. So somehow windows changed the shortcut path to
 the directory on the remote machine, great eh !
 
 All is now working ok, but I have lost over a weeks LL testing because of
 it. No harm seems to have been done to the remote machine.
 
 Regards,
 
 Mike,
 
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Mersenne: Bold Predictions From STL's Mysterious Ways

1999-10-16 Thread STL137

(I'm quite poor at choosing subjects, you see.)

Well, I found my notecard of predictions that I had calculated a while ago 
with my conjecture. Here are some of the values I computed. These can either 
be used for a good laugh (M100 in particular is nice to look at), or you can 
write these values down and see how close they hit the mark (live long and 
find Mersennes?). At the time I only had data for Mersenne prime exponents up 
to 3021377 (i.e. not 6972593), and I calculated what M37 should have been as 
a test. It's pretty close. My prediction for the 6M prime was also close. 
Now, to find the missing Mersenne

Here I call M# to be q instead of 2^q-1 for brevity.

M37 (known at the time to actually be 3021377): 3166795
M38: 4673434 (the elusive missing Mersenne?!? If there is no Mersenne prime 
around here, then the 3021377-6972593 gap is almost as large as the 127-521 
gap!)
M39: 6896873 (There is a prime at 6972593 in this region. But is it M38 or 
M39?)
M40: 10178139
M41: 15020505
M42: 22166682
M43: 32712733
M44: 48276189 (hence my conjecture that the decamegaprime is either right at 
the 10M digit limit, or has an exponent around 48M)
M50: 498689073
M75: 8379797036294
M100 ~ 14081118310500 (that's its EXPONENT, whoo hoo. The inaccuracy is 
due to the precision limitations of my calculator)

As for myself, I'm *really* hoping that there's a missing Mersenne. Time will 
tell

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Mersenne: Re: AMD K6 and Athlon

1999-10-16 Thread Steinar H. Gunderson

On Sat, Oct 16, 1999 at 03:47:42PM -0400, Jud McCranie wrote:
I tried version 19 on a PII and a Celeron, and in both cases it thought 
they were P-Pros.  It got the MHz correct.

Were these upgraded, or fresh installs? The GIMPS software (still no
collective name for Prime95/Saver95/mprime/ntprime?) won't try a
redetection if there already is a CPU type entry available.

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Mersenne: Re: Reliability (was Re: splitting up 10m digit primes) + Possible Wish List item

1999-10-16 Thread Steinar H. Gunderson

On Sat, Oct 16, 1999 at 06:27:24AM +0300, Jukka Santala wrote:
If you can afford the bandwidth and storage
space, you can check the box.

The problem probably doesn't lie at the user's end. The server is the one
with the storage problem, and probably the one with the bandwidth problem
as well...

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Re: Mersenne: Bold Predictions From STL's Mysterious Ways

1999-10-16 Thread Darxus


STL: what was the line you fit to the log log of the known mersenne's
exponents, and what was the error (r^2) ?

I'm assuming r^2 is like, the amount of error for a given line fitting a
set of data.

When I fit an exponential line to the 1st 37 mersenne prime's exponents
(since I believe that 6972593 is actually the 39th, but have no proof, so
I figured I'd leave it out), the line I got was y=1.7661e^0.301x (hope I
wrote that right), and r^2=0.9925.

I have a feeling the log log thing will actually be more useful.. easier
to predict a straight line than an exponential curve.

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Re: Mersenne: Re: AMD K6 and Athlon

1999-10-16 Thread George Woltman

Hi,

At 02:22 AM 10/17/99 +0200, Steinar H. Gunderson wrote:
On Sat, Oct 16, 1999 at 03:47:42PM -0400, Jud McCranie wrote:
I tried version 19 on a PII and a Celeron, and in both cases it thought 
they were P-Pros.  It got the MHz correct.

Were these upgraded, or fresh installs? The GIMPS software (still no
collective name for Prime95/Saver95/mprime/ntprime?) won't try a
redetection if there already is a CPU type entry available.

Prime95 does not detect Celerons very well.  However, if a PIII, PII or
Celeron is detected as a Pentium Pro - its no big deal.  All those CPU
types use the same code.

Regards,
George

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Re: Mersenne: The Mysterious Ways of S.T.L.

1999-10-16 Thread Darxus

On Fri, 15 Oct 1999 [EMAIL PROTECTED] wrote:


 Then, I plotted e^gamma log[2] (mersenne) versus the list of 1-37.  Alongside 
 this I graphed y=x. This is because the y=x line represents the Wagstaff 

y=x would be a slope of 1/1.

According to the "Where is the next larger Mersenne prime?" page --
http://www.utm.edu/research/primes/notes/faq/NextMersenne.html the
Wagstaff conjecture suggests a slope of 3/2, which I believe wouldn't look
so bad.

 So, I graphed e^gamma log [2] (mersenne) - (1, 2, 3, 4, etc). This represents 
 how far off the Wagstaff conjecture is when applied to the data. (The 
 Wagstaff conjecture *should* say that M(3021377) = 37, but it doesn't. This 
 is why I graph this jibberish). This graph was INCREDIBLY disturbing. Save 
 for one Mersenne prime, all these "errors" were above 0, and often big. Ech! 
 So, I used my TI-92+ to take a linear regession line of this data (because I 
 had recently learned how to do regression lines and correlation 
 coefficients). This line was Y = .004769x + 1.4615. See what's happening 
 here? It seems that there's a consistent error (1.4615) in the Wagstaff 
 conjecture that doesn't change as the Mersenne primes grow (the .004769).  So 
 I went back and applied this correction to the graph "that seemed a little 
 strange" and it fit y=x much better.

Sorry it didn't register to me that you'd mentioned the equation for this
line in this post, thanks.  But what was r^2 for it ?  I'm very curious.

On the previously mentioned web page, there are similar computations, but
I believe he used M38 (which you and I believe will actually turn out to
be M39), so I believe his numbers will be less accurate than yours.

I would really like to try your calculations myself, but I haven't seen my
graphing calculator for a while, I'm not sure it'd work, and I'd prefer to
use the power of my computer.  Can anybody suggest any programs ?
Preferably for Linux, even though that would mean I'd have to wait to get
my Linux drive back.

I am most anxious to take M1-M36  extrapolate M37, down through having
just, say, M1-M10  extrapolating M11  see how accurate that process is.  


I really thing the GIMPS client should have an option to test the mersenne
number closest to this estimate of M38 that has not been and is not being
tested -- implemented in a scalable fasion, so that when/if the missing
prime is found, and it finishes the number it's on (since knowing what
isn't prime is valuble), it'll then go to the next estimated prime.

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