Primes p such that p^2 + 1 divides 3^(p+1) - 1.A343768Primes p such that p^2 + 1 divides 3^(p+1) - 1.Terms a(0) =3a(1) =5a(2) =47a(3) =1091a(4) =172681External referencesoeis: A343768