Proof-code: L521
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  Samuel Yates began, and this site continues, a database of the largest known primes. Primes in that database are assigned a proof-code to show who should be credited with the discovery as well as what programs and projects they used. (Discoverers have one prover-entry, but may have many proof-codes because they use a variety of programs...) This page provides data on L521, one of those codes.

Code name (*):L521   (See the descriptive data below.)
Persons (*):1 (counting humans only)
Projects (*):1 (counting projects only)
Display (HTML):Thompson1, Gcwsieve, MultiSieve, PrimeGrid, LLR
Number of primes:total 1
Unverified Primes:0 (prime table entries marked 'Composite','Untested', or 'InProcess')
Score for Primes (*):total 47.0073, on current list 47.0073 (normalized score 26)
Entrance Rank (*):mean 13.00 (minimum 13, maximum 13)

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On 21 Dec 2007, 10:09:30 UTC, PrimeGrid's Woodall Prime Search found the 33rd and largest known to date Woodall prime. It's the first found mega-digit prime using LLR.

The discovery was made by Matthew J. Thompson of the United States using an Intel P4 @ 2.8 GHz with 512 MB RAM. This computer took almost 15 hours and 11 minutes to test.

The prime was verified on 24 Dec 2007, 1:10:44 UTC, by an AMD Athlon64 X2 3600+ with 2GB RAM. This computer took a little over 24 hours 55 minutes to test.

This is PrimeGrid's third Woodall prime. Since the search began, just over 134,000 tests have been completed by 4524 users using 9149 computers.

Using a single PC would have taken years to find this prime. So this timely discovery would not have been possible without the hundreds of volunteers who contributed their spare CPU cycles. A special thanks to everyone who contributed their advice and/or computing power to the search - especially Brian Rodenkirk, Lennart Vogel, Joseph M. Osiecki, Geoffrey Reynolds, and Paul Underwood.

Additional thanks to all the sievers who prepared the work for PrimeGrid: Sievers.

PrimeGrid's Woodall Prime Search will continue to search for even larger Woodall Primes. To join the search please visit PrimeGrid:

Below is additional information about this entry.
Display (text):Thompson1, Gcwsieve, MultiSieve, PrimeGrid, LLR
Display (short):Thompson1
Database id:3476 (do not use this database id, it is subject to change)
Proof program:LLR  The primes from this code accounts for 0.021% of the (active) primes and 0.044% of the (active) score for this program.
Entry last modified:2017-10-18 15:20:13