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Old 2020-05-18, 17:40   #2
kriesel's Avatar
Mar 2017
US midwest

423210 Posts

Originally Posted by LOBES View Post
I recently found the 2641st largest prime known to mankind (fame to come I'm sure) using the Genefer 16 sub-project at PrimeGrid. The number is 93043462^65536 + 1

Because I simply enjoy it, I would like to test this number manually using Prime95 but I'm not exactly sure how I would format the entry in worktodo.txt?

What would be the proper syntax for testing this number, if of course, its even possible?
A direct quote from the prime95 readme.txt file:
The PRP choice, available from the menus only in the Mac OS X version, lets you do a
probable prime test on numbers of the form k*b^n+c.  On all OSes, you can edit
the worktodo.txt file directly.  For example add:
where the how_far_factored and tests_saved values are used to pick
 optimal bounds for P-1 factoring prior to running the PRP test.
Should not take long to run compared to current GIMPS work.
PRP=N/A,1,93043462,65536,1,86,2 inserted into the worktodo.txt file and run, indicates ~73 minutes on my Win10 i7-8750H in the worker window, with a 192K fft length, but oddly about 10 years estimate in the status option. I'm inclined to believe the worker.
For GIMPS worktodo formats in general, see

edit: as Batalov reminds in the next post, PRP does not prove it prime; it can show something composite but can't prove it prime. It at best indicates probably prime with a high probability.
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Last fiddled with by kriesel on 2020-05-18 at 17:56
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