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 A342395 #12 Mar 10 2021 12:28:50
%S A342395 1,3,12,90,1305,15713,376768,6163324,176787369,3769360335,
%T A342395 142364319636,3152514811878,154718778284161,4340009168261557,
%U A342395 210971169749009040,7281661102087491416,435659030617933827153,14181101408651996188995
%N A342395 a(n) = Sum_{k=1..n} k^(n/gcd(k,n)).
%F A342395 If p is prime, a(p) = A121706(p) + p.
%t A342395 a[n_] := Sum[k^(n/GCD[k, n]), {k, 1, n}]; Array[a, 18] (* _Amiram Eldar_, Mar 10 2021 *)
%o A342395 (PARI) a(n) = sum(k=1, n, k^(n/gcd(k, n)));
%Y A342395 Cf. A121706, A332620, A342389, A342396.
%K A342395 nonn,easy
%O A342395 1,2
%A A342395 _Seiichi Manyama_, Mar 10 2021