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 A342449 #28 Mar 13 2021 10:59:32
%S A342449 1,5,29,262,3129,46705,823549,16777544,387421251,10000003469,
%T A342449 285311670621,8916100581446,302875106592265,11112006826387025,
%U A342449 437893890391180013,18446744073743123788,827240261886336764193,39346408075299116257065
%N A342449 a(n) = Sum_{k=1..n} gcd(k,n)^k.
%F A342449 If p is prime, a(p) = p-1 + p^p = A231712(p).
%t A342449 a[n_] := Sum[GCD[k, n]^k, {k, 1, n}]; Array[a, 20] (* _Amiram Eldar_, Mar 13 2021 *)
%o A342449 (PARI) a(n) = sum(k=1, n, gcd(k, n)^k);
%Y A342449 Cf. A000010, A001923, A018804, A050873, A231712, A332517, A341036, A342370, A342389, A342423.
%K A342449 nonn
%O A342449 1,2
%A A342449 _Seiichi Manyama_, Mar 13 2021