> >> If trial-factoring has been done up to 2^68... is it > >> possible to skip testing ECM curves for factors up to 15 > >> and/or 20 digits... and go straight to testing ECM curves > >> for digits up to 25 digits??? > > > Personally, I would go straight in at the 25+ digits level. > > OTOH, if trial factoring has been done to 2^68 on a Mersenne > number then the number is probably quite big (IIRC) so it will take a long > time to run just a single curve with a big B1.
Sure, but which would you rather do: run a 10-hour program once with a 1/1000 chance of finding a factor, or run a 1-hour program 10 times which has a total 1/1100 chance of finding a factor? Don't take the figures literally, but they are illustrative of the sorts of choices that have to be made. In the end you place your bets and you take your chance. Paul _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
