OFFSET
1,1
COMMENTS
Base 18 Wieferich primes. According to Richard Fischer there is no other term up to approximately 5*10^13.
LINKS
Amir Akbary and Sahar Siavashi, The Largest Known Wieferich Numbers, INTEGERS, 18(2018), A3. See Table 1 p. 5.
R. Fischer, Thema: Fermatquotient B^(P-1) == 1 (mod P^2)
MATHEMATICA
Select[Prime[Range[1000000]], PowerMod[18, # - 1, #^2] == 1 &] (* Robert Price, May 17 2019 *)
PROG
(PARI) forprime(n=2, 10^9, if(Mod(18, n^2)^(n-1)==1, print1(n, ", ")));
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Felix Fröhlich, Jun 24 2014
STATUS
approved