Re: Mersenne: Re: Mersenne Digest V1 #843

2001-04-29 Thread Peter-Lawrence . Montgomery
Brian J. Beesley [EMAIL PROTECTED] wrote, in response to my earlier message The point of course is that there is a formal proof that, if a prime p is congruent to 3 modulo 4 and 2p+1 is also prime, then 2^p-1 is divisible by 2p+1 - which makes searching for a factor of M(p) by trying

Re: Mersenne: Re: Mersenne Digest V1 #843

2001-04-28 Thread Brian J. Beesley
On 28 Apr 2001, at 0:57, [EMAIL PROTECTED] wrote: Question (deep) - if we did discover a factor of 2^(2^727-1)-1, would that help us to find a factor of 2^727-1 ? The reason for asking this question was twofold: firstly, to find out whether it _might_ be possible to know a factor of 2^c-1

Re: Mersenne: Re: Mersenne Digest V1 #843

2001-04-27 Thread Peter-Lawrence . Montgomery
On 26 Apr 2001, Brian J. Beasley wrote On 26 Apr 2001, at 6:34, Hans Riesel wrote: Hi everybody, If 2^p-1 is known to be composite with no factor known, then so is 2^(2^p-1)-1. Much as I hate to nitpick a far better mathematician than myself, this is seems to be an

Re: Mersenne: Re: Mersenne Digest V1 #843

2001-04-26 Thread Brian J. Beesley
On 26 Apr 2001, at 6:34, Hans Riesel wrote: Hi everybody, If 2^p-1 is known to be composite with no factor known, then so is 2^(2^p-1)-1. Much as I hate to nitpick a far better mathematician than myself, this is seems to be an overstatement. It is certainly true that, for composite c,

Re: Mersenne: Re: Mersenne Digest V1 #843

2001-04-25 Thread Nathan Russell
On Thu, 26 Apr 2001 06:34:07 +0200 (MET DST), Hans Riesel wrote: Hi everybody, If 2^p-1 is known to be composite with no factor known, then so is 2^(2^p-1)-1. For that matter, the same argument can be made with regard to 2^(2^R-1)-2 for some RSA factoring challange number R, and probably

Re: Mersenne: Re: Mersenne Digest V1 #843

2001-04-25 Thread Spike Jones
Hans Riesel wrote: Hi everybody, If 2^p-1 is known to be composite with no factor known, then so is 2^(2^p-1)-1. Hans Riesel It has been a long time since I have seen a more elegant argument ender than this. Thanks Hans! spike