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

0,2

Links

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

Formula

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

Mathematica

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

Prog

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

Crossrefs

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

Sequence in context: A234952 A112041 A210425 * A002060 A247739 A007220

Adjacent sequences: A366687 A366688 A366689 * A366691 A366692 A366693

Keyword

nonn

Author

Sean A. Irvine, Oct 16 2023

Status

approved