a(n) = (2^prime(n) + 1)/3.

A126614

a(n) = (2^prime(n) + 1)/3.

Terms

    a(0) =3a(1) =11a(2) =43a(3) =683a(4) =2731a(5) =43691a(6) =174763a(7) =2796203a(8) =178956971a(9) =715827883a(10) =45812984491a(11) =733007751851

External references