Eric Hahn wrote:
>
> I'm looking for program(s) capable of trial-factoring
> prime exponent Mersenne numbers (using 2kp+1) meeting
> the following requirements:
>
> [factors and exponents of arbitrary size]
>
mersfacgmp from the Will Edgingtons mers package uses gmp's mpz type for
factors (thus the size of the factor is only limited by your available
memory) and long ints for the exponent. If you have a 64 bit cpu, that
should allow exponentes up to 18446744 trillion.
> I just know somebody is going to have to mention the
> time involved in testing factors of such a large size.
> Let me just say, I realize *exactly* how much time
> would be required...
Ok, but know that gmp is not particulary efficient on "small" number of
only a few dozend decimals, the time required might be what you expect
and then some.
> 3) Capable of trial-factoring a range of k's.
> (example: from k=1000 to k=2500)
Hmmm, I dont think mersfacgmp can process this directly, but it would be
easy to compute the proper factoring limits with a shell script that
calls bc.
The mers package can be found on Will's home page,
http://www.garlic.com/~wedgingt/mersenne.html
Ciao,
Alex.
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