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 A377674 #10 Nov 04 2024 01:36:26 %S A377674 1,2,8,96,1248,12000,259200,5461344,129140160,2725643520,127561104000, %T A377674 2743415522496,139778722137600,2504616361228800,111747349423990784, %U A377674 8644660582219776000,387774574486565683200,12306643656809728412160,816897235219321957908480 %N A377674 a(n) = phi(n^n + n) where phi is the Euler totient function. %H A377674 Amiram Eldar, <a href="/A377674/b377674.txt">Table of n, a(n) for n = 1..116</a> %F A377674 a(n) = A000010(A066068(n)). %t A377674 a[n_] := EulerPhi[n^n + n]; Array[a, 20] (* _Amiram Eldar_, Nov 04 2024 *) %o A377674 (PARI) a(n) = eulerphi(n^n+n); %Y A377674 Cf. A000010, A066068, A366822, A372228, A372546, A377671, A377672, A377673. %K A377674 nonn %O A377674 1,2 %A A377674 _Sean A. Irvine_, Nov 03 2024