In response to the message from... From: Yann Forget <[EMAIL PROTECTED]> Subject: Mersenne: Fermat number & others Hi, I have a few questions which are not in the FAQ : - - What about testing F24 with Pepin's test ? (http://www.utm.edu/research/primes/glossary/PepinsTest.html) Is there a code for this ? On Intel (MS Windows or Linux) ? Is there some machine running this ? How long would it take to test the primality of F24 with a PII (for ex.) -------------[end of quoted portion of message]---------------- Fermat number F24 has been discussed on the list before, quite a while ago. I think testing F24 by Pepin's test would take about the same amount of computation as an LL test of a Mersenne number with an exponent of about 2^24 (16777216). Based on how long it takes to do an LL test with prime95, I would estimate that testing F24 with a PII would take perhaps 6 months to a year. A lot depends on how fast the multi-precision arithmetic routines are, of course. I am not aware of any existing software for this that is readily available, but writing one's own program using existing "big number" arithmetic routines shouldn't be very difficult. Actually, it seems quite probable that someone, somewhere, is already in the process of testing F24. (No, I don't have any details -- it just seems likely.) And, no I am not testing F24. Instead, I am trying to figure out how to find a factor of F14. --Jim Howell _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
