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 A308481 #15 Mar 28 2024 21:56:32
%S A308481 1,1,9,82,1300,15626,376761,6161988,176787117,3769318700,142364319625,
%T A308481 3152513804548,154718778284148,4340009120036086,210971169748692000,
%U A308481 7281661100510001416,435659030617933827136,14181101408561469791694,1052864393300587929716721,41673894815421072916530408
%N A308481 a(n) = Sum_{k=1..n, gcd(n,k) = 1} k^n.
%H A308481 Seiichi Manyama, <a href="/A308481/b308481.txt">Table of n, a(n) for n = 1..386</a>
%t A308481 a[n_] := Sum[If[GCD[n, k] == 1, k^n, 0], {k, 1, n}]; Table[a[n], {n, 1, 20}]
%o A308481 (PARI) a(n) = sum(k=1, n, (gcd(n,k)==1)*k^n) \\ _Felix Fröhlich_, May 30 2019
%Y A308481 First superdiagonal of A308477.
%Y A308481 Cf. A031971.
%K A308481 nonn
%O A308481 1,3
%A A308481 _Ilya Gutkovskiy_, May 30 2019