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 A342423 #14 Mar 12 2021 09:10:43
%S A342423 1,5,29,262,3129,46693,823549,16777484,387420549,10000003145,
%T A342423 285311670621,8916100495490,302875106592265,11112006826381589,
%U A342423 437893890380865741,18446744073726329368,827240261886336764193,39346408075296925089309
%N A342423 a(n) = Sum_{k=1..n} gcd(k,n)^gcd(k,n).
%H A342423 Seiichi Manyama, <a href="/A342423/b342423.txt">Table of n, a(n) for n = 1..386</a>
%F A342423 a(n) = Sum_{d|n} phi(n/d) * d^d.
%t A342423 a[n_] := Sum[GCD[k, n]^GCD[k, n], {k, 1, n}]; Array[a, 18] (* _Amiram Eldar_, Mar 11 2021 *)
%o A342423 (PARI) a(n) = sum(k=1, n, gcd(k, n)^gcd(k, n));
%o A342423 (PARI) a(n) = sumdiv(n, d, eulerphi(n/d)*d^d);
%Y A342423 Cf. A000010, A332517, A342420, A342424.
%K A342423 nonn
%O A342423 1,2
%A A342423 _Seiichi Manyama_, Mar 11 2021