A355959 - OEIS

%I #13 Aug 27 2023 16:42:25

%S 5,45827

%N Primes p such that (p+2)^(p-1) == 1 (mod p^2).

%C a(3) > 107659373057 if it exists.

%C Primes p such that the Fermat quotient of p base 2 (A007663) is congruent to 1/2 modulo p. - _Max Alekseyev_, Aug 27 2023

%o (PARI) forprime(p=1, , if(Mod(p+2, p^2)^(p-1)==1, print1(p, ", ")))

%Y (p+k)^(p-1) == 1 (mod p^2): A355960 (k=5), A355961 (k=6), A355962 (k=7), A355963 (k=8), A355964 (k=9), A355965 (k=10).

%Y Cf. A007663.

%K nonn,hard,more,bref

%O 1,1

%A _Felix Fröhlich_, Jul 21 2022