A366623 a(n) = phi(6^n-1), where phi is Euler's totient function (A000010).

4, 24, 168, 864, 6200, 30240, 223944, 1119744, 7457184, 37200000, 277618528, 1254113280, 10445497920, 51618196224, 365601600000, 1770091315200, 13439285266176, 62336092492800, 484935499902880, 2179146240000000, 17141125020596640, 86330728271779200

Offset

1,1

Links

Max Alekseyev, Table of n, a(n) for n = 1..420

Formula

a(n) = A000010(A024062(n)). - Paul F. Marrero Romero, Oct 23 2023

Mathematica

EulerPhi[6^Range[22] - 1] (* Paul F. Marrero Romero, Oct 23 2023 *)

Prog

(PARI) {a(n) = eulerphi(6^n-1)}

Crossrefs

phi(k^n-1): A053287 (k=2), A295500 (k=3), A295501 (k=4), A295502 (k=5), this sequence (k=6), A366635 (k=7), A366654 (k=8), A366663 (k=9), A295503 (k=10), A366685 (k=11), A366711 (k=12).

Cf. A024062, A000010, A295502, A366620, A366621, A366622.

Sequence in context: A213441 A238299 A221656 * A339346 A214377 A331007

Adjacent sequences: A366620 A366621 A366622 * A366624 A366625 A366626

Keyword

nonn

Author

Sean A. Irvine, Oct 14 2023

Status

approved