gsmith@brahms (Gene Ward Smith) (11/16/86)
Could someone send me the most up to date information about known Mersenne primes? I am interested in knowing what "gaps", if any, remain unchecked, and what is at present the largest known prime. (I know a mathematician who is ready to began Mersenne-finding, but needs to know *where*). ucbvax!brahms!gsmith Gene Ward Smith/UCB Math Dept/Berkeley CA 94720 ucbvax!weyl!gsmith Institute of Pi Research
bs@linus.UUCP (Robert D. Silverman) (11/17/86)
> > > Could someone send me the most up to date information about known > Mersenne primes? I am interested in knowing what "gaps", if any, remain > unchecked, and what is at present the largest known prime. (I know a > mathematician who is ready to began Mersenne-finding, but needs to know > *where*). > > ucbvax!brahms!gsmith Gene Ward Smith/UCB Math Dept/Berkeley CA 94720 > ucbvax!weyl!gsmith Institute of Pi Research The largest known Mersenne prime is 2^216091 - 1. It was found by a Cray computer in about 3 hours of testing using a program written by Slowinski. Much to the chagrin of mathematicians, however, Mr. Slowinski does not test numbers systematically, but rather jumps around quite a bit in the hope of setting records. His feeling is that 'most' of the numbers below 216091 have been tested but noone knows for sure which ones may have been missed. The second largest exponent is 132049. All numbers have been tested up to this. Anyone looking for Mersenne primes is going to need a lot of computer time. It takes about 3 hours on a Cray X-MP to test a single number around 2^200000-1. Bob Silverman