OFFSET
1,1
LINKS
Eric Weisstein's World of Mathematics, Double Wieferich Prime Pair
EXAMPLE
a(2) = 83, because 83 is the smallest prime q such that A266829(2) = 4871 satisfies both 4871^(q-1) == 1 (mod q^2) and q^(4871-1) == 1 (mod 4871^2).
PROG
(PARI) forprime(p=3, , forprime(q=2, p-1, if(Mod(p, q^2)^(q-1)==1 && Mod(q, p^2)^(p-1)==1, print1(q, ", "); break)))
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Felix Fröhlich, Aug 05 2018
STATUS
approved