Hi all, The first results are in from version 17.0 535 results have been reported with 7 mismatched residues. Of those 7, 2 had errors reported during the version 17.0 run. Thus, very preliminary data indicates that if you get an error-free double-check run under version 17, then there is about 1 in 100 chance that you are doing a first-time check that could find a new Mersenne prime. Actually, the odds could be lower as I assumed the 5 mismatches were due to a bad initial run as opposed to a bad version 17 run. Unfortunately, my database is not well enough organized to know whether any errors were reported on the initial run of those 5 numbers. I'll post updated numbers at a later date. Best regards, George