View Single Post 2007-11-05, 12:14   #6
Mini-Geek
Account Deleted

"Tim Sorbera"
Aug 2006
San Antonio, TX USA

10AB16 Posts Quote:
 Originally Posted by rong123 So if the number above was indeed the lowest 2^n-1, n=M3321928094, Would I be able to start factoring this Mersenne number using trial factoring? Like I was saying in my original post Factoring all the way up to something like n^74 starting in the chronology like i was saying n^1, n^2...etc? Like when Prime95 grabs an assignment for trial factoring and puts it on your worktodo.ini example: Factor=3321928094,1 then Factor=3321928094,2 etc.. Factor=3321928094,74 OR do I have this all wrong? I am using the Factor=n thinking it is the same as what I was saying above being n^1, n^2, etc..n^74
In Prime95 v24 (which is the current stable version), Factor=3321928094,2 tells Prime95 that it has been factored to 2 bits, not that you should factor it to 2 bits. What it is factored to is determined automatically, or by setting a line in the prime.ini file forcing it to factor all numbers to that bit.
In Prime95 v25 (which is an alpha preview version), you use Factor=3321928094,2,70 to say that it has been factored to 2 bits and that you want to factor it to 70 bits.

Also, for a Mersenne number to possibly be prime, the exponent must be prime. (http://en.wikipedia.org/wiki/Mersenn...ersenne_primes for a description of why) That is, in 2^n-1, n must be prime. 3321928094 isn't prime. The next prime from that is 3321928097.  