One of my machines recently finished a double check and apparently
the residue did not match. I go look at the details for this exponent
http://www.mersenne.org/report_expon...9761383&full=1
and it has had three LL tests run and none of the residues match.
Does this happen a lot?
Trivia question: Which exponent has had the most number of
(unmatching residue) LL tests done on it? (I don't know.)