A366690 a(n) = phi(11^n+1), where phi is Euler's totient function (A000010).

1, 4, 60, 432, 7320, 53680, 803520, 6495720, 100874752, 764738496, 12756110400, 89493288192, 1568774615040, 11278053084480, 180228847518720, 1310982643872000, 22974417331646464, 168479281019744640, 2521788545778163200, 20190830281379049600

Offset: 0

Author

Sean A. Irvine, Oct 16 2023

Keywords

• nonn

Links

• Max Alekseyev, Table of n, a(n) for n = 0..325

Crossrefs

Cf. A034524, A000010, A062308, A366685, A366686, A366687, A366689, A366689, A366716.

Programs

Mathematica

EulerPhi[11^Range[0,19] + 1] (* Paul F. Marrero Romero, Nov 10 2023 *)

PARI

{a(n) = eulerphi(11^n+1)}

Formula

a(n) = A000010(A034524(n)). - Paul F. Marrero Romero, Nov 10 2023