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 A350109 #19 Dec 16 2021 08:41:28
%S A350109 1,6,32,295,3201,48321,828323,16910106,388005909,10019717653,
%T A350109 285409876785,8920506515453,302901435774351,11113364096436947,
%U A350109 437903477186179875,18447307498823123948,827244767844150424228,39346708569526147402819
%N A350109 a(n) = Sum_{k=1..n} k * floor(n/k)^n.
%H A350109 Seiichi Manyama, <a href="/A350109/b350109.txt">Table of n, a(n) for n = 1..386</a>
%F A350109 a(n) = Sum_{k=1..n} k * Sum_{d|k} (d^n - (d - 1)^n)/d.
%F A350109 a(n) = [x^n] (1/(1 - x)) * Sum_{k>=1} (k^n - (k - 1)^n) * x^k/(1 - x^k)^2.
%F A350109 a(n) ~ n^n. - _Vaclav Kotesovec_, Dec 16 2021
%t A350109 a[n_] := Sum[k * Floor[n/k]^n, {k, 1, n}]; Array[a, 18] (* _Amiram Eldar_, Dec 14 2021 *)
%o A350109 (PARI) a(n) = sum(k=1, n, k*(n\k)^n);
%o A350109 (PARI) a(n) = sum(k=1, n, k*sumdiv(k, d, (d^n-(d-1)^n)/d));
%Y A350109 Main diagonal of A350106.
%Y A350109 Cf. A319194, A332469.
%K A350109 nonn
%O A350109 1,2
%A A350109 _Seiichi Manyama_, Dec 14 2021