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 SB13, one of those codes.
Database query returned no results. One possibility is that you mistyped the URL. You might try using the links in the menu to browse the index or search this site. If you think there is an error in the system, go to the home page and e-mail the technical editor.
This page displays a single proof-code. To do so, you must specify which using just one of the following.