OFFSET
1,1
COMMENTS
A Wieferich prime p (A001220) is in this sequence iff neither A000040(i-1) nor A000040(i+1) is a Wieferich prime, where i is the index of p in A000040.
Conjecture: There are no consecutive Wieferich primes, i.e., A001220 is a subsequence of this sequence.
The truth of the previous conjecture would follow from the truth of the heuristic assumption that there are about log(log(x)) Wieferich primes below x for large x.
PROG
(PARI) a196202(n) = lift(Mod(2, n^2)^(n-1))
is(n) = (ispseudoprime(n)) && (a196202(n) < a196202(precprime(n-1))) && (a196202(n) < a196202(nextprime(n+1)))
CROSSREFS
KEYWORD
nonn
AUTHOR
Felix Fröhlich, May 27 2017
STATUS
approved