The first few Mersenne primes are 3, 7, 31, 127 and 8191. These numbers took a total of several weeks to verify, using different software and hardware. Each number was independently checked by several members of GIMPS' verification team, using 16-core systems of different configurations. The two primes were announced by GIMPS on September 16. Before these two discoveries, the two previously largest known prime numbers were discovered by UCMO professors Curtis Cooper and Steven Boone in Missouri, United States, and their record lasted almost three years. Historically, prime numbers discovered by GIMPS are larger than the one previously found. The only other exception was when the 29th Mersenne prime was discovered after the 30th and 31st were found. Founded by M.I.T. graduate George Woltman in 1996, GIMPS has found 12 Mersenne primes, or about one per year on average.
Steve Boone is a member of GIMPS.