20050115, 19:19  #1 
Dec 2004
13×23 Posts 
How do I prove a 4000 digit number is prime??
I have one 31digit factor from a number of the k*2^n+1 type where n=~7300,
How do I check if the "Cofactor" is prime, it ends in ....1162049124129 Thanks 
20050115, 19:40  #2 
Dec 2004
13×23 Posts 
Not to get everyone excited I don't think the cofactor is prime, but how do I check or continue to find factors of this "cofactor"...

20050115, 20:30  #3 
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 
20050115, 21:35  #4 
Jul 2004
Potsdam, Germany
3·277 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. 
20050509, 20:56  #5  
"Jason Goatcher"
Mar 2005
3505_{10} Posts 
Quote:
Am I breaking any laws if I use this software? Edit: I'm a US resident in Arkansas. Last fiddled with by jasong on 20050509 at 20:57 

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