Shoichiro Yamada's geneferCUDA
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program A titan, as defined by Samuel Yates, is anyone who has found a titanic prime. This page provides data on those that have found these primes. The data below only reflect on the primes currently on the list. (Many of the terms that are used here are explained on another page.)

Proof-code(s): p332, p334, p338, L2975, L3118, L3184, L3230
E-mail address:
Web page:
Username: geneferCUDA (entry created on 11/05/2011)
Database id:3193 (entry last modified on 07/04/2015)
Active primes:on current list: 7, rank by number 24
Total primes: number ever on any list: 7
Production score: for current list 51 (normalized: 1559), rank by score 17
Largest prime: 475856524288 + 1 ‏(‎2976633 digits) via code L3230 on 08/14/2012
Most recent: 475856524288 + 1 ‏(‎2976633 digits) via code L3230 on 08/14/2012
Entrance Rank: mean 18.29 (minimum 11, maximum 24)

Descriptive Data: (report abuse)
GeneferCUDA is a derived work based upon algorithms by Yves Gallot. It is a command line program for testing Generalized Fermat primes (b^2^n+1). It is designed to utilize CUDA. Double precision GPU required, so compute capability 1.3 or higher, meaning a GForce GTX 260 or better. See the web page for additional details.

For details on the original algorithm, see Yves Gallot's genefer.c program which can be found at

David Underbakke and Mark Rodenkirch assisted with many of the new features such as the checkpoint file, quick calculate mode, progress reporting, and residual values.
Ken Brazier assisted developed CUDA version.
Iain Bethune assisted developed Mac and Linux version.
Michael Goetz developed BOINC and CUDA version.
Ronald Schneider developed Linux version.

Note: This program identifies probable primes. The probable prime must be proven with another program before being submitted.

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Surname: GeneferCUDA (used for alphabetizing and in codes)
Unverified primes are omitted from counts and lists until verification completed.