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 A321438 #16 Sep 08 2022 08:46:23
%S A321438 1,3,28,239,3126,45990,823544,16711423,387440173,9990235398,
%T A321438 285311670612,8913939907598,302875106592254,11111328602501550,
%U A321438 437893920912786408,18446462594437808127,827240261886336764178,39346258082220810086373,1978419655660313589123980,104857499999905732078938574
%N A321438 a(n) = Sum_{d|n} (-1)^(n/d+1)*d^n.
%H A321438 Seiichi Manyama, <a href="/A321438/b321438.txt">Table of n, a(n) for n = 1..386</a>
%F A321438 G.f.: Sum_{k>=1} (k*x)^k/(1 + (k*x)^k).
%F A321438 L.g.f.: log(Product_{k>=1} (1 + k^k*x^k)^(1/k)) = Sum_{n>=1} a(n)*x^n/n.
%F A321438 a(n) ~ n^n. - _Vaclav Kotesovec_, Nov 10 2018
%t A321438 Table[Sum[(-1)^(n/d + 1) d^n, {d, Divisors[n]}], {n, 20}]
%t A321438 nmax = 20; Rest[CoefficientList[Series[Sum[(k x)^k/(1 + (k x)^k), {k, 1, nmax}], {x, 0, nmax}], x]]
%t A321438 nmax = 20; Rest[CoefficientList[Series[Log[Product[(1 + k^k x^k)^(1/k), {k, 1, nmax}]], {x, 0, nmax}], x] Range[0, nmax]]
%o A321438 (PARI) a(n) = sumdiv(n, d, (-1)^(n/d+1)*d^n); \\ _Michel Marcus_, Nov 09 2018
%o A321438 (Magma) m:=20; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!( (&+[(k*x)^k/(1+(k*x)^k): k in [1..m]]) )); // _G. C. Greubel_, Nov 11 2018
%Y A321438 Cf. A000593, A023887, A078306, A078307, A186633, A284900, A284926, A284927, A321385.
%K A321438 nonn
%O A321438 1,2
%A A321438 _Ilya Gutkovskiy_, Nov 09 2018