- Oh dear, Paul, it seems that 252601=41*61*101
turned you off Fermat-Lucas when n^2=1 mod 5.
FYI, I shall post 49,285 such double-pseudoprimes
(I think, but no checking has been done!)
in the files area.
I hope someone will check that these
are all 2-sPrP and Fibonacci-PrP.
I was amazed by how prolific they appear to be.
None is congruent to 2 or 3 (mod 5),
so no $620 cigar, of course!
[goes to post file..]
OK .... file is (I hope)
> 2-sPrP Fibonacci pseudoprimes to 52 bitsThanks to Jason, for the 2-sPrP part.
Can someone check this bestiary, please?
David (about to disappear on another trip)