Re: How do I do very big integer computing by Mathematica?

*To*: mathgroup at smc.vnet.net*Subject*: [mg115375] Re: How do I do very big integer computing by Mathematica?*From*: a boy <avvboy at gmail.com>*Date*: Sun, 9 Jan 2011 02:19:42 -0500 (EST)

I asked how to do very-big-integer computing. For example: Mod[2^2^64,1342352] It's pity, this code causes overflow! is there some funtions like this: StringMod["111...111","345"] On Sun, Jan 9, 2011 at 8:17 AM, Daniel Lichtblau <danl at wolfram.com> wrote: > > ----- Original Message ----- > > From: "a boy" <avvboy at gmail.com> > > To: mathgroup at smc.vnet.net > > Sent: Saturday, January 8, 2011 2:37:07 AM > > Subject: [mg115335] How do I do very big integer computing by > Mathematica? > > I'm going to search big Fibonacci prime numbers. I think there is a > > simple primality test algorithm for Fibonacci number, like Lucas=96 > > Lehmer primality test for 2^n-1 . I'm lazy and don't want to write > > many codes. So i want to ask: > > > > p=43,112,609; > > s[0]=4; > > s[n_]:=s[n-1]^2-4 > > pt=Mod[s[p-2], 2^p-1]==0 > > > > how do I compute s[43,112,609-2] directly? It seems the largest > > integer in M~ is 2^32^32, isn't it? > > Not exactly certain what you want to do from that description. But > something that might help is to interleave Mod[] operations provided the > modulus is not too large for Mathematica. > > Daniel Lichtblau > Wolfram Research > > >