> From: Brian J. Beesley [mailto:[EMAIL PROTECTED]] > What I mean is that 10^100 = 3 + (10^100 - 3) is one possible > breakdown. But I don't know offhand whether (10^100 - 3) is prime, > and proving that it is might take some considerable time. If that However, proving it is composite is very easy. It is divisible by 13. > fails, I can skip 5 + (10^100 - 5) and 7 + (10^100 - 7) since in each > case the larger number is clearly composite. But, in general, I'd > have to check whether (10^100 - p) is prime for every odd prime p > until I find a prime (proving that Goldbach's Conjecture holds for > the specific odd number 10^100) or until p > 0.5 * 10^100 (a > counterexample!) 1.96 seconds on a PII-300 and Francois Morain's ECPP program shows that 10^100-797 is prime. Running a composite test on all the other larger candidates took 1.80 seconds in total. Paul _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
