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Old 2014-11-07, 21:40   #3
Madpoo
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Jul 2014

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Quote:
Originally Posted by TheMawn View Post
I feel like questionable results ought to have high priority, whether it's a first-time with error(s) or a failed DC.
I might have to figure out some good way of showing which exponents would be good candidates for triple-checks.

The good (or bad?) news is that none of the triple-checks I've completed so far for exponents that had reported prime are all composite after all.

There was one that I didn't want to mention that got checked in last year (July 2013) that said it was prime, and hadn't even had a double-check yet. I was under the impression it had been checked by someone else but I didn't see any records of it. It's composite though. :) But of course now it'll need a triple-check to verify my result.

http://www.mersenne.org/M60404837

Here's one I'm triple-checking now and should have a good triple-check in another couple days (45 hours to be exact):
http://www.mersenne.org/M53878507

In general, there aren't that many LL tests needing a triple-check, and if it does need one, then it'll get assigned using the normal double-check process. I do think that false positives for being prime deserve a good triple-check right away though. I imagine they probably are most of the time. I looked back here on the forum for other examples when false positives came to light, and it looked like George had a few folks checking them out simultaneously on multiple systems.

It might just be that the ones I found had their Prime95 verification checked in, but whoever did another verification CudaLucas or something didn't get that result checked in. Which would be a shame of course, but I could see that happening.

By the way, sometimes a residue is all zeros *except* for the last digit, like maybe a 2 or a 4 or whatever . Since the last 2 digits are masked unless it's verified, I think some people have spotted those in the results and thought that might be the hidden prime.

So, for the record, yes, it does happen, and maybe it's a bug similar to what causes false positives in the first place, but there are over a dozen where the residue is all zeros except the last 1 or 2 digits. :) Enjoy!
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