A211875 Primes of the form Phi(phi(k),3), the phi(k)-th Cyclotomic polynomial evaluated at 3, where phi is the Euler totient function.

2, 7, 61, 73, 6481, 530713, 42521761, 47763361, 23535794707, 282429005041, 374857981681, 150094634909578633, 13490012358249728401, 105919308797935444986721, 1076050302914923449767311155851656076154481

Offset

1,1

Links

Table of n, a(n) for n=1..15.

Mathematica

Union[Select[Cyclotomic[EulerPhi[#], x] /. x -> 3 & /@ Range[1000], PrimeQ]]

Crossrefs

Sequence in context: A366328 A091687 A000892 * A065397 A255904 A046846

Adjacent sequences: A211872 A211873 A211874 * A211876 A211877 A211878

Keyword

nonn

Author

Alexander Gruber, Feb 12 2013

Status

approved