This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A366690 #12 Jan 04 2024 17:09:56
%S A366690 1,4,60,432,7320,53680,803520,6495720,100874752,764738496,12756110400,
%T A366690 89493288192,1568774615040,11278053084480,180228847518720,
%U A366690 1310982643872000,22974417331646464,168479281019744640,2521788545778163200,20190830281379049600
%N A366690 a(n) = phi(11^n+1), where phi is Euler's totient function (A000010).
%H A366690 Max Alekseyev, <a href="/A366690/b366690.txt">Table of n, a(n) for n = 0..325</a>
%F A366690 a(n) = A000010(A034524(n)). - _Paul F. Marrero Romero_, Nov 10 2023
%t A366690 EulerPhi[11^Range[0,19] + 1] (* _Paul F. Marrero Romero_, Nov 10 2023 *)
%o A366690 (PARI) {a(n) = eulerphi(11^n+1)}
%Y A366690 Cf. A034524, A000010, A062308, A366685, A366686, A366687, A366689, A366689, A366716.
%K A366690 nonn
%O A366690 0,2
%A A366690 _Sean A. Irvine_, Oct 16 2023