Quote:
Originally Posted by paulunderwood
Add to the above list the recent find: 3*2^801978+1. The gap between John Cosgrove's search and Adney's must be almost nil.

Keith has a way to go. John went up to 2,600,000 and had many PCs working on it. I don't know how many PCs Keith has, but there are almost twice as many even exponents are there are odd exponents. There are a few years of PRP testing left to get the even exponents up to 2,600,000. As long as Keith finds primes (and I'm surprised he has found two), he will probably continue. If anyone wants to assist, they are welcome to take a range.