On 2 Dec 2001, at 19:57, Gordon Spence wrote:
> >From: "Steve Harris" <[EMAIL PROTECTED]>
> >
> >George did say that, and I was aware of his statement, but that still has no
> >effect on the point I was making.
> >George's GIMPS stats also give no credit at all for finding factors,
>
> Tell me about it, over 150,000 and no mention anywhere....
Ah, but George's GIMPS stats encourage factoring by removing LL
testing credit when a factor is subsequently found. (Either you
should have done more factoring before you started LL testing, or
the factoring you did was expensive!)
> >From: [EMAIL PROTECTED]
> >
> >The other problem here is that the "known factors" database does
> >not include the discoverer.
>
> A particularly sore point. If we maintained a top "savers" list whereby for
> every factor found you were credited with the time an LL test would have
> taken, then I and the other "Lone Mersenne Hunters" would pulverise these
> big university teams.
Umm... let's put it this way. Who gets the credit for finding the
factor 2p+1 when p+1 is divisible by 4 and both p & 2p+1 are
prime? That's a _big_ bunch of numbers ... I'm not sure that there
are an infinite number of 3 mod 4 Sophie Germain primes, but there
certainly are a _lot_ of them... and I think you have to credit them
all to the person who proved the theorem.
>
> 150,000 factors in the 60-69m range, at an average of 27.2 P-90 years each
> - hmmmm just over 4,000,000 years saved....
With due respect, I don't think it's entirely reasonable to award
credit for more effort than was actually expended, or for more effort
than it would have taken to run two LL tests.
I think some realistic formula for finding the factor 2kp+1 would look
like:
k>=2^64 2 x LL test CPU time
2^63 <= k < 2^64 1 x LL test CPU time
2^62 <= k < 2^63 0.5 x LL test CPU time
2^61 <= k < 2^62 0.25 x LL test CPU time
etc etc
_provided_ that no credit was given for factoring work which failed
to find a factor.
However there are clearly philosophical differences here as well as
practical ones - what Gordon says is clearly absolutely true in the
literal sense.
Possibly the best idea is the simplest - leave the current
procedures alone!
Regards
Brian Beesley
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