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 A341036 #22 Mar 13 2021 10:58:51
%S A341036 1,2,5,19,129,1306,16813,262181,4783059,100000214,2357947701,
%T A341036 61917372083,1792160394049,56693912393474,1946195068811453,
%U A341036 72057594039243049,2862423051509815809,121439531096661117354,5480386857784802185957
%N A341036 a(n) = Sum_{k=1..n} gcd(k,n)^(k-2).
%t A341036 a[n_] := Sum[GCD[k, n]^(k - 2), {k, 1, n}]; Array[a, 20] (* _Amiram Eldar_, Mar 13 2021 *)
%o A341036 (PARI) a(n) = sum(k=1, n, gcd(k, n)^(k-2));
%Y A341036 Cf. A000010, A018804, A342370, A342432, A342449.
%K A341036 nonn
%O A341036 1,2
%A A341036 _Seiichi Manyama_, Mar 13 2021