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Old 2010-02-02, 05:05   #42
gd_barnes's Avatar
May 2007
Kansas; USA

1014610 Posts

There were 4 primes found by Lennart on the public server that were not found by Bruce in his manual LLRnet run that effectively was a double-check of a large part of the range. Triple-checking by me confirmed that Bruce's list is correct. Here are the culprits:

2457*2^239794-1 is not prime. LLR Res64: 55D32DAFD42FB9B4 Time : 198.913 sec.
2463*2^170838-1 is not prime. LLR Res64: EC031A0DB6C2DCF2 Time : 127.062 sec.
2481*2^185187-1 is not prime. LLR Res64: A64A60A7D5942FD4 Time : 119.079 sec.
2505*2^154470-1 is not prime. LLR Res64: 07BE4011A7E08FF5 Time : 89.002 sec.

In all 4 cases, these were close to actual primes that were found by both Bruce and Lennart. They are:
2457*2^239814-1 (n=20 difference from above "composite prime")
2463*2^170842-1 (n=4 difference)
2481*2^185218-1 (n=31 difference)
2505*2^154475-1 (n=5 difference)

That is exactly what happened to me on 2 occassions when I had a laptop with bad memory. It would find a "composite prime" very close to an actual prime. I'll send Lennart a PM referencing this post. I have now deleted the erroneous primes from the 1st post here.

That's a start on the cleanup of k=2400-2600 here...still much work to do on it later Tuesday.


Last fiddled with by gd_barnes on 2010-02-02 at 05:49
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