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 A321385 #12 Dec 01 2018 08:20:54
%S A321385 1,3,28,251,3126,46632,823544,16776955,387420517,9999996878,
%T A321385 285311670612,8916100401824,302875106592254,11112006824734476,
%U A321385 437893890380862528,18446744073692774139,827240261886336764178,39346408075296150201567,1978419655660313589123980,104857599999999989999997126
%N A321385 a(n) = Sum_{d|n} (-1)^(n/d+1)*d^d.
%H A321385 Seiichi Manyama, <a href="/A321385/b321385.txt">Table of n, a(n) for n = 1..386</a>
%F A321385 G.f.: Sum_{k>=1} k^k*x^k/(1 + x^k).
%F A321385 a(n) ~ n^n. - _Vaclav Kotesovec_, Nov 09 2018
%t A321385 Table[Sum[(-1)^(n/d + 1) d^d, {d, Divisors[n]}], {n, 20}]
%t A321385 nmax = 20; Rest[CoefficientList[Series[Sum[k^k x^k/(1 + x^k), {k, 1, nmax}], {x, 0, nmax}], x]]
%o A321385 (PARI) a(n) = sumdiv(n, d, (-1)^(n/d+1)*d^d); \\ _Michel Marcus_, Nov 09 2018
%Y A321385 Cf. A000312, A062796, A321387.
%K A321385 nonn
%O A321385 1,2
%A A321385 _Ilya Gutkovskiy_, Nov 08 2018