Re: Factors for 2^n -1, n>400 and n even
- Thank you Mr.Steven and Mr.Paul.
--- In firstname.lastname@example.org, Steven Whitaker <steven@w...> wrote:
> On Mon, 05 Sep 2005 15:56:45 -0000, you wrote:
> >I am looking for a pre-computed table of the prime factorization of
> >2^n -1,400<n<500 and n is even.
> >I am only able to find the prime factorization for all odd powers in
> >the above range from the table below.
> >I have been using pari to compute the factorisation without much
> >success. Any help is appreciated.
> There is an algebraic factorisation for even exponents:
> 2^(2n)-1 = (2^n-1)(2^n+1)
> So there's no point in recording them separately. (Read the introduction
> to the short tables in that paper).
> Incidentally, there is a more up-to-date list at the Cunningham project