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Igor Schein on Thu, 08 May 2014 18:45:36 +0200
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Re: Factoring small numbers
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- To: Jeroen Demeyer <jdemeyer@cage.ugent.be>
- Subject: Re: Factoring small numbers
- From: Igor Schein <igorschein@gmail.com>
- Date: Thu, 8 May 2014 12:45:25 -0400
- Cc: pari-dev <pari-dev@pari.math.u-bordeaux1.fr>
- Delivery-date: Thu, 08 May 2014 18:45:36 +0200
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On Thu, May 8, 2014 at 12:40 PM, Jeroen Demeyer <jdemeyer@cage.ugent.be> wrote:
> Dear pari-dev,
>
> While working on Sage today, I was very amazed that GAP is much faster than
> PARI for factoring small numbers.
>
> For example, for factoring 19180172397815991981, GAP beats PARI by a factor
> of about 20. As far as I know, PARI uses rho + MPQS while GAP only uses
> Pollard rho. So perhaps PARI shouldn't use MPQS for numbers of this size.
>
> Any opinions?
>
>
> Cheers,
> Jeroen.
>
gp takes under 3ms to factor 19180172397815991981. Hard to beat that IMO.
Igor