A366716 a(n) = phi(12^n+1), where phi is Euler's totient function (A000010).

1, 12, 112, 1296, 20416, 229680, 2306304, 32916240, 400515072, 3863116800, 47825825600, 685853880624, 8732596764672, 97509650382144, 990242755633152, 11148606564480000, 184883057981234176, 2047145911595946000, 20281543142263603200, 294779525244632305920

Offset

0,2

Links

Max Alekseyev, Table of n, a(n) for n = 0..306

Formula

a(n) = A000010(A178248(n)). - Paul F. Marrero Romero, Oct 27 2023

Mathematica

EulerPhi[12^Range[0, 19] + 1] (* Paul F. Marrero Romero, Oct 27 2023 *)

Prog

(PARI) {a(n) = eulerphi(12^n+1)}

Crossrefs

Cf. A178248, A000010, A366711, A366712, A366713, A366714, A366715, A366719, A366720, A366690.

Sequence in context: A265948 A016152 A089700 * A290742 A268767 A221368

Adjacent sequences: A366713 A366714 A366715 * A366717 A366718 A366719

Keyword

nonn

Author

Sean A. Irvine, Oct 17 2023

Status

approved