From: bs@gauss.mitre.org (Robert D. Silverman)
Newsgroups: sci.math,sci.crypt
Subject: New Mersenne Prime
Date: 26 Mar 92 14:35:38 GMT

Cray has just announced the discovery of a new Mersenne prime. It
is 2^756839 - 1 and is over 3 times the size of the last one. It was
discovered by a Cray-2 in England. It has 227,832 digits.

Computational number theorists are concerned over this announcement
because we would like to know whether this is the NEXT Mersenne prime.
In the past people at Cray have jumped around, hoping to set a record,
rather than searching through increasing exponents systematically.

The discovery would have MUCH more value if we knew there were no more
Mersenne primes between 2^216091 -1 (the last one discovered) and the new
one. Walter Colquitt checked the entire range from 216091 to 365,000 without
finding any, but we'd like to know whether there can be any between 365K and the
new one. Otherwise all this means is marketing hype and publicity for Cray.
I would like to note that on one occassion a Mersenne prime WAS discovered that
was smaller than the largest known. It was discovered by Colquitt and had
fallen through the cracks of the people at Cray.

--
Bob Silverman
These are my opinions and not MITRE's.
Mitre Corporation, Bedford, MA 01730
"You can lead a horse's ass to knowledge, but you can't make him think"