RE: Mersenne: Common practice for P-1 math?

2000-06-15 Thread Paul Leyland
I wrote: From: Brian J. Beesley [mailto:[EMAIL PROTECTED]] If P-1 does find a factor which is compound, then running P-1 again with smaller limits will eventually recover a smaller factor. These extra runs will obviously take less time than the original Indeed, and with care one

Mersenne: Common practice for P-1 math?

2000-06-14 Thread Will Edgington
I was wondering if it was common practice (ie: the norm) for P-1 to take the product of two or more factors when giving out a found factor, if two of more factors are found? Yes, if both factors are "smooth" enough, they could be found as their product, rather than individually.

Re: Mersenne: Common practice for P-1 math?

2000-06-14 Thread Brian J. Beesley
On 12 Jun 00, at 23:20, Eric Hahn wrote: I was wondering if it was common practice (ie: the norm) for P-1 to take the product of two or more factors when giving out a found factor, if two of more factors are found? I don't know about "common practice", but P-1 uses GCD to find the factor.

RE: Mersenne: Common practice for P-1 math?

2000-06-14 Thread Paul Leyland
From: Brian J. Beesley [mailto:[EMAIL PROTECTED]] If P-1 does find a factor which is compound, then running P-1 again with smaller limits will eventually recover a smaller factor. These extra runs will obviously take less time than the original Indeed, and with care one can usually choose

RE: Mersenne: Common practice for P-1 math?

2000-06-14 Thread Brian J. Beesley
On 14 Jun 00, at 4:49, Paul Leyland wrote: It's a pity that a similar procedure isn't known for ECM, or at least not known to me. Isn't the point that ECM finds numerically small factors much more easily than it finds numerically large factors? Therefore, if a "reasonable" amount of trial

RE: Mersenne: Common practice for P-1 math?

2000-06-14 Thread Paul Leyland
From: Brian J. Beesley [mailto:[EMAIL PROTECTED]] On 14 Jun 00, at 4:49, Paul Leyland wrote: It's a pity that a similar procedure isn't known for ECM, or at least not known to me. Isn't the point that ECM finds numerically small factors much more easily than it finds numerically

Mersenne: Common practice for P-1 math?

2000-06-13 Thread Eric Hahn
Greetings all, I was wondering if it was common practice (ie: the norm) for P-1 to take the product of two or more factors when giving out a found factor, if two of more factors are found? To clarify, I was curious about how P-1 would indicate more than one factor being found. So, I took

Re: Mersenne: Common practice for P-1 math?

2000-06-13 Thread Alexander Kruppa
Eric Hahn wrote: Greetings all, I was wondering if it was common practice (ie: the norm) for P-1 to take the product of two or more factors when giving out a found factor, if two of more factors are found? Yup, each factor f, for which b^E == 1 (mod f) (b is the base, usually 3, E is