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-   -   What about double-checking TF/P-1? (https://www.mersenneforum.org/showthread.php?t=16626)

 137ben 2012-03-12 02:22

What about double-checking TF/P-1?

While it is possible for an error in a TF to "miss" a found factor, it probably isn't worth the effort to double check. However, it may well be worth checking that found factors are actually factors, to be sure that we don't miss any Mersenne primes. It would be a lot easier that the initial round of trial factoring, because we would only need to check TF assignments for which a found factor was reported. Since this is relatively rare, (and in fact, TF jobs in which factors are found tend to take much less time than those which find no factors), it shouldn't take very much effort to do, and it helps ensure that we do not miss any primes.
So, anyone else think this is a good idea?

 LaurV 2012-03-12 04:18

There is NO EFFORT needed to check a factor. The process is straight forward and it is done automatically by the server. Imagine you want to factor 123509 using only pencil and paper, it will take you a while and your only perspective would be to check all primes below 350 or so, but if I tell you that 113 is a factor, you will not need more then few seconds to say if that is true or not. Checking if some x is a factor of some y need no effort. The problem is that these possible x-es are sooooo many, and we have difficulties to "choose" the right one...

 Xyzzy 2012-03-12 04:50

 Mini-Geek 2012-03-12 22:14

[QUOTE=LaurV;292665]There is NO EFFORT needed to check a factor.[/QUOTE]

To be technically correct: The effort needed to check a factor [of a typical Mersenne number GIMPS handles] is trivial, but not zero.

 davieddy 2012-03-12 22:26

Is this Pussy Heaven?

[URL="http://www.youtube.com/watch?v=MvarLqTNr1M"]Not Roy Orbison or Dennis Hopper[/URL]

David

Or even this:

Even Homer nods

 Uncwilly 2012-03-13 00:11

[QUOTE=Mini-Geek;292796]To be technically correct: The effort needed to check a factor [of a typical Mersenne number GIMPS handles] is trivial, but not zero.[/QUOTE]Vanishingly small, might be a better term.

 Christenson 2012-03-13 04:01

How about the amount of computational effort to check a found factor is on the same order of effort as transmitting it over the internet and receiving it at the server.

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