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 A354508 #14 Aug 16 2022 10:21:03
%S A354508 1,5,32,168,1189,8785,77384,646296,7306737,79997893,1005481784,
%T A354508 12518370128,184109233125,2671256865121,47934480000112,
%U A354508 754158322407248,13813898274148737,262680987222463269,5518034466415262320,107988236156057411096,2605128008760639636677
%N A354508 a(n) = n! * Sum_{k=1..n} ( Sum_{d|k} (-1)^(k/d+1) * d^2 )/(k * (n-k)!).
%F A354508 a(n) = n! * Sum_{k=1..n} A078306(k)/(k * (n-k)!).
%F A354508 E.g.f.: -exp(x) * Sum_{k>0} (-x)^k/(k * (1 - x^k)^2).
%F A354508 E.g.f.: exp(x) * Sum_{k>0} k * log(1 + x^k).
%o A354508 (PARI) a(n) = n!*sum(k=1, n, sumdiv(k, d, (-1)^(k/d+1)*d^2)/(k*(n-k)!));
%o A354508 (PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(-exp(x)*sum(k=1, N, (-x)^k/(k*(1-x^k)^2))))
%o A354508 (PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(exp(x)*sum(k=1, N, k*log(1+x^k))))
%Y A354508 Cf. A354506, A354507.
%Y A354508 Cf. A078306, A356391.
%K A354508 nonn
%O A354508 1,2
%A A354508 _Seiichi Manyama_, Aug 15 2022