mersenneforum.org How do I prove a 4000 digit number is prime??
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 2005-01-15, 19:19 #1 VJS     Dec 2004 13×23 Posts How do I prove a 4000 digit number is prime?? I have one 31-digit factor from a number of the k*2^n+1 type where n=~7300, How do I check if the "Co-factor" is prime, it ends in ....1162049124129 Thanks
 2005-01-15, 19:40 #2 VJS     Dec 2004 13×23 Posts Not to get everyone excited I don't think the co-factor is prime, but how do I check or continue to find factors of this "co-factor"...
 2005-01-15, 20:30 #3 VJS     Dec 2004 13·23 Posts I'll try http://www.alpertron.com.ar/ECM.HTM You can put use raw interger numbers... in addition to equations. It will do a Rabin probabilistic prime check
 2005-01-15, 21:35 #4 Mystwalker     Jul 2004 Potsdam, Germany 14778 Posts Lately, I've found Primo, which seems to be a relatively fast primalty proving program for numbers of no special form. Unfortunately, 4000 digits will most likely still take several weeks or even months. It seems like Jens Franke et. al have a distributed primalty proving program, though.
2005-05-09, 20:56   #5
jasong

"Jason Goatcher"
Mar 2005

66618 Posts

Quote:
 Originally Posted by Mystwalker Lately, I've found Primo, which seems to be a relatively fast primalty proving program for numbers of no special form. Unfortunately, 4000 digits will most likely still take several weeks or even months. It seems like Jens Franke et. al have a distributed primalty proving program, though.
I went to the website and discovered some comments about the US, Canadian, and Japanese patent laws being so overly patent-happy(my word) that the writer fears getting sued. The thing is, even though he says the usage is forbidden the download proceeds without a hitch.

Am I breaking any laws if I use this software?

Edit: I'm a US resident in Arkansas.

Last fiddled with by jasong on 2005-05-09 at 20:57

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