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 A369904 #6 Jun 26 2024 14:59:59
%S A369904 0,1,1,6,1,18,1,28,12,36,1,100,1,62,42,120,1,189,1,208,68,138,1,456,
%T A369904 30,188,117,364,1,612,1,496,144,312,86,1038,1,386,194,960,1,1080,1,
%U A369904 820,477,558,1,1936,56,955,318,1120,1,1782,162,1688,392,876,1,3336,1,998,789
%N A369904 a(n) = n * Sum_{p|n, p prime} sigma(n/p) / p.
%F A369904 a(p^k) = p^(k-1)*(p^k-1)/(p-1), for prime p and k >= 1. - _Wesley Ivan Hurt_, Jun 26 2024
%t A369904 Table[n*DivisorSum[n, DivisorSigma[1, n/#]/# &, PrimeQ[#] &], {n, 100}]
%Y A369904 Cf. A000203 (sigma), A323599, A329354, A369740, A369903.
%K A369904 nonn,easy
%O A369904 1,4
%A A369904 _Wesley Ivan Hurt_, Feb 05 2024