Loading ...
Sorry, an error occurred while loading the content.

Re: Factors for 2^n -1, n>400 and n even

Expand Messages
  • jtrjtrjtr2001
    Thank you Mr.Steven and Mr.Paul. Sarad.
    Message 1 of 4 , Sep 5, 2005
    • 0 Attachment
      Thank you Mr.Steven and Mr.Paul.

      Sarad.

      --- In primenumbers@yahoogroups.com, Steven Whitaker <steven@w...> wrote:
      > On Mon, 05 Sep 2005 15:56:45 -0000, you wrote:
      >
      > >hi,
      > >
      > >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.
      > >http://www.ams.org/online_bks/conm22/conm22-whole.pdf
      > >
      > >I have been using pari to compute the factorisation without much
      > >success. Any help is appreciated.
      > >
      > >Sarad.
      >
      >
      > Sarad
      >
      > 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
      > website:
      >
      > http://homes.cerias.purdue.edu/~ssw/cun/index.html
      >
      > Regards
      > Steve
    Your message has been successfully submitted and would be delivered to recipients shortly.