1,1

Double Wieferich prime pairs are pairs of primes (p, q) such that q^(p-1) == 1 (mod p^2) and p^(q-1) == 1 (mod q^2). a(n) is a subset of A123692(n) = {2, 20771, 40487, 53471161, 1645333507, 6692367337, 188748146801, ...} Primes p such that p^2 divides 5^(p-1) - 1.

C. K. Caldwell, The Prime Glossary, Fermat quotient.

Cf. A124121, A124122, A123692, A125775.

Adjacent sequences: A126429 A126430 A126431 this_sequence A126433 A126434 A126435

Sequence in context: A034616 A084551 A104944 this_sequence A071372 A129474 A015411

bref,hard,more,nonn

Alexander Adamchuk (alex(AT)kolmogorov.com), Mar 12 2007