On Tuesday 28 January 2003 06:08, Mary K. Conner wrote: > > I'm speaking of triple or higher checks where all residues > agree. The only reason to do those other than the exponents that have only > 16 bit residues is to check for cheating. If those kinds of checks need to > be done, they ought to be done with intelligence, not by random poaching. > As someone who has done a fair number of these, and is continuing to run, I think I am operating responsibly. I am selecting for triple-checking those exponents where both (or all) the entries in lucas_v.txt were contributed by the same user id.
So the only way I would be "poaching" is if someone else has already "poached". Naturally the situation will sometimes arise by chance that LL test and DC on a particular exponent happen to be assigned to the same user, particularly those who process a lot of exponents. I'm also aware there are other ways of cheating, but this method seems likely if the idea is to boost league table rankings. As it happens, I have not found any evidence of cheating, but I have exposed a problem which resulted in a few (very few, well, two to be exact) exponents being accepted as "double checked" resulting (I think) from a single run being reported twice. This work is complete up to the mid-5 million range; the leading edge is just below 6 million. The total number of exponents involved is not enormous. As I proceed, I'm also completing any trial factoring which might have been missed, and running P-1 to "high memory LL test limits". A number of exponents have been eliminated from lucas_v by finding a factor. Incidentally, one of the factors I found (but only one, so far) has appeared in my PrimeNet personal status report. I don't know why this should be. I have a couple of people working with me on this. If anyone else would like to get involved, please e-mail me. But don't expect exponents significantly smaller than those you might get for normal DC assignments. I'm also working, at low priority & again with a couple of helpers, at completing triple-checking for all small exponents (under 1 million). Why? So far as I'm concerned, it's something useful for a couple of slow systems to do whilst they're acting as room heaters! I certainly don't regard this sub-project as "important", it's just that the systems I'm employing are too slow to be of much use to PrimeNet, even for factoring assignments. Regards Brian Beesley _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
