20180318, 08:21  #485 
Basketry That Evening!
"Bunslow the Bold"
Jun 2011
40<A<43 89<O<88
3·29·83 Posts 
Much like gapcoin, I've always thought a coin that finds zeros of the RiemannZeta function would be fun.

20180318, 18:13  #486 
Aug 2006
1011011100100_{2} Posts 

20180403, 23:39  #487 
∂^{2}ω=0
Sep 2002
República de California
10101110100100_{2} Posts 
While poking around on the skywatching site EarthSky.org, happened across this 9. January piece:
http://earthsky.org/humanworld/larg...ersenneprimes 
20180417, 21:53  #488  
"Marv"
May 2009
near the Tannhäuser Gate
1E7_{16} Posts 
Quote:
http://en.wikipedia.org/wiki/ZetaGrid 

20180517, 20:44  #489 
Sep 2003
2578_{10} Posts 
M77232917 was confirmed by a bunch of programs, including gpuOwL. But Jacobi checking was mentioned, so that was an early version of the program, with LL testing rather than PRP.
It would be useful to run PRP tests on the largest known Mersenne primes, or perhaps even all of them, just to test whether the code and the server do the right thing when a discovery is made. Will the server send emails? This seems like a useful sanity check and dry run. Maybe one PRP test with gpuOwL and one with mprime. I could post worktodo lines for these. 
20181214, 20:14  #490  
"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest
EFD_{16} Posts 
Quote:
Actually running a large fraction of known Mersenne primes on the latest gpuOwL would provide both runtime scaling data, and some confidence regarding whether it is subject to false negatives. I'm in the process of doing that now. Results will appear in https://www.mersenneforum.org/showthread.php?t=23391 It's not possible to run gpuOwL PRP tests on _all_ known Mersenne primes, because gpuOwl through V5.09c13870 has a minimum fft length of 128K. The lowest it handles properly is M31, p=216091, with ~1.65 bits/word. (That Mersenne prime was originally found by a Cray supercomputer.) It is possible to run PRP from p=3 up using prime95/mprime for known Mersenne primes, since prime95 has fft lengths down to 32 (words, not 32K). I've done it recently up to p~3M to generate a quick runtime scaling data set. It spins through the first 25 Mersennes on one core of an old slow i3 in a couple seconds total. See the attachment at https://www.mersenneforum.org/showpo...78&postcount=2 Last fiddled with by kriesel on 20181214 at 20:17 

20181214, 20:45  #491  
Sep 2003
2·1,289 Posts 
Quote:
For exponents smaller than 1M, the tests would take less than a minute with mprime, mostly far less. I think at one point I tested those small Mersenne primes with a very simple C implementation of LucasLehmer and also PRP with a simple GMP modular exponentiation function call, but didn't properly note and record the results. So, anyways, if you're PRP testing the nonsmall Mersenne primes on gpuOwL and I'm doing it with mprime, then the two efforts will complement each other. There is no doubt what the result will be, but it bugs me that this simple sanity check has apparently never been done. Or if it has, there is no record of it. 

20181214, 21:11  #492  
P90 years forever!
Aug 2002
Yeehaw, FL
3×2,281 Posts 
Quote:
That email process has been working quite well. Last fiddled with by Prime95 on 20181214 at 21:11 

20191221, 21:17  #493 
"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest
3·1,279 Posts 
What, 4 days to Christmas, and no encore with Mp52?

20191222, 04:37  #494 
6809 > 6502
"""""""""""""""""""
Aug 2003
101×103 Posts
3×7×383 Posts 

20191223, 20:05  #495 
∂^{2}ω=0
Sep 2002
República de California
25644_{8} Posts 
Perhaps all those Defense Department supercomputers which are normally secretly repurposed to searching for the next holiday prime around this time of year are unavailable this year, thanks to an unfortunate typo:
NORAD Tracking Satan for the Holidays due to Typo  Duffel Blog 
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