The OEIS is supported by the many generous donors to the OEIS Foundation.
Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
%I #11 Jan 07 2024 12:05:48
%S 1,6,36,180,1296,6000,41472,230496,1580800,8359200,58579200,310968900,
%T 2175102720,10971642240,76065091200,351048600000,2811459796992,
%U 14508487949472,88870766837760,522016066337712,3564233663616000,17479898551382400,128060205344805888
%N a(n) = phi(6^n+1), where phi is Euler's totient function (A000010).
%H Max Alekseyev, <a href="/A366630/b366630.txt">Table of n, a(n) for n = 0..420</a>
%F a(n) = A000010(A062394(n)). - _Paul F. Marrero Romero_, Oct 17 2023
%t EulerPhi[6^Range[0, 22] + 1] (* _Paul F. Marrero Romero_, Oct 17 2023 *)
%o (PARI) {a(n) = eulerphi(6^n+1)}
%Y Cf. A062394, A000010, A366623, A366618, A366627, A366628, A366629, A366670.
%Y Cf. A053285, A366579, A366608, A366618, A366639, A366658, A366667, A366669, A366690, A366716.
%K nonn
%O 0,2
%A _Sean A. Irvine_, Oct 14 2023