At 04:46 PM 2/10/2000 -0800, you wrote:
>Do ALL exponents get Double-Checked? ...or are only selected exponents
>done because the original LL run was suspect?
>
>Just curious,
>Russ
Suspect exponents get done earlier.
All are to get double checked eventually.
A mersenne prime is not said to be proven the Nth mersenne
prime until after all prime exponents below it have matching
double or triple or higher checks. (Single checks showing
compositeness could be in error, hiding another prime.)
For QA test purposes, due to poaching, or because of errors in
multiple runs, quite a few get triple checked and a few get
quadruple checked.
Assume that a set of 400,000 exponents get single checked,
and double checked, and the error rate per check is 0.5%.
If the error occurrence is independent, that means about 4000
will not match. Of these 4000 then the triple checks would
have errors in about 20, and require a quadruple check which
most likely would match one of the previous results.
Already double or triple checked exponents make the best check
values for a new program.
Ken
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