Mersenne: FAQ registered with search engines

1999-07-19 Thread Lucas Wiman
I added the FAQ to the following search engines: Lycos Excite Yahoo Altavista AOL netfind Webcrawler HotBot InfoSeek -Lucas _ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasa

RE: Mersenne: The $100,000 award for 10,000,000 digit prime

1999-07-19 Thread Todd Sauke
Alex, The group you seek always has 2^n elements. All bit combinations are possible. (P = 2^p-1 is "minus one" in n-bit words. 2*P is minus two, etc. up to 2^n*P which is 0. All bit patterns occur.) Todd Sauke >Now, I'm going to toss out an idea. I thought about this a few minutes >after r

Re: Mersenne: Worth it?

1999-07-19 Thread David M Einstein
Disclaimer: All my commentary is based on recollections of what I did a few years ago. I believe that there are comments in an archive somewhere by Peter Montgomery and George Woltman conatining much more accurate info. Lucas Wiman wrote: > > Sorry if this is sending out twice, I wasn't sure tha

RE: Mersenne: The $100,000 award for 10,000,000 digit prime

1999-07-19 Thread Alex Healy
Thanks. I was also considering a base other than base 2. But I'm afraid the same problem arises as long as the base is realatively prime to the Mersenne number we are considering. For example if you look at 2047 (i.e. 2^11 - 1) in base 23 or base 87 you'll see the algorithm I outline below actu

Mersenne Digest V1 #600

1999-07-19 Thread Mersenne Digest
Mersenne Digest Monday, July 19 1999 Volume 01 : Number 600 -- Date: Sun, 18 Jul 1999 23:03:52 +0100 From: "Brian J. Beesley" <[EMAIL PROTECTED]> Subject: Re: Mersenne: Setu for Dual processor NT > Is there

RE: Mersenne: The $100,000 award for 10,000,000 digit prime

1999-07-19 Thread Alex Healy
Now, I'm going to toss out an idea. I thought about this a few minutes after reading the previous message and I want to see if you all think its worthwhile or not, or whether its even correct or not. Here goes: 1) If we know the last n bits of a number x, then we can (easily) determine the last n

Re: Mersenne: The $100,000 award for 10,000,000 digit prime

1999-07-19 Thread Brian J. Beesley
On 19 Jul 99, at 3:57, [EMAIL PROTECTED] wrote: >*) Somebody finds how to parallelize the FFT using little >communication. The wall-clock time might be reduced 10-fold, >but the CPU time increased 16-fold. This could be >great for verifying a new Mer

Re: Mersenne: Worth it?

1999-07-19 Thread Lucas Wiman
Sorry if this is sending out twice, I wasn't sure that it got sent the first time... >> As I understand the Pollard P-1 algorithm, the time required for 1 bit of >> the exponent would be equal to 1 iteration of the LL test (one squaring >> mod Mp), so values wouldn't be that hard to create. (timi

Re: Mersenne: A slight divergence...

1999-07-19 Thread Peter-Lawrence . Montgomery
Chris Jefferson <[EMAIL PROTECTED]> writes > It is well known that n is prime if for all prime factors of n-1, a^(n-1) > = 1 mod n and a^((n-1)/q) is not 1 mod n. What are a and q? You want to say `if for each prime factor q of n-1, there exists a base a such that ...' . > For example, ta

Mersenne: A slight divergence...

1999-07-19 Thread Chris Jefferson
It is well known that n is prime if for all prime factors of n-1, a^(n-1) = 1 mod n and a^((n-1)/q) is not 1 mod n. For example, take a=2, and 2^p+1 (p is prime, yes, that IS a plus) Then we need to check if 2^(2^p)=1 mod (2^p -1) and 2^((2^p)/2) is not 1. Now, we know that 2^p = 1 mod (2^p - 1

Mersenne: A busy computer is a happy computer - SunWorld - July 1999

1999-07-19 Thread David L. Nicol
introductory article re: distributed computing, decent GIMPS paragraph. http://www.sunworld.com/swol-07-1999/swol-07-silicon.html?0719i _ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ --

Re: Mersenne: Worth it?

1999-07-19 Thread Lucas Wiman
> We should try to increase this probability before starting any > full LL test, perhaps by using better factoring algorithms. > Will v19 have P-1 code that works with numbers of this size? > But even with P-1, we might not be able to factor that much > further. The time consuming part of P-1 are

Mersenne: Worth it?

1999-07-19 Thread Alex Kruppa
Hi, from stuff I saw on the list earlier I put together this estimate: The chance for Mp being prime if it has no factor below 2^q is 2q/p (if q is reasonably big, at i.e. 2^q much bigger than 2p+1). If we test the Mersennes in the 10M-digits range for factors to, say, 2^80, the chance for, say