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 A356406 #14 Aug 05 2022 15:36:54
%S A356406 1,4,16,79,443,2968,22216,189698,1792402,18745036,213452996,
%T A356406 2653142952,35448861576,509724975264,7824794618208,128006170541328,
%U A356406 2217950478978576,40686737647774368,785852762719168992,15974195890305405696,340376906088298319616
%N A356406 a(n) = n! * Sum_{k=1..n} Sum_{d|k} 1/(d * (k/d)^d).
%F A356406 E.g.f.: -(1/(1-x)) * Sum_{k>0} log(1 - x^k/k).
%F A356406 a(n) = n! * Sum_{k=1..n} A308345(k)/k!.
%o A356406 (PARI) a(n) = n!*sum(k=1, n, sumdiv(k, d, 1/(d*(k/d)^d)));
%o A356406 (PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(-sum(k=1, N, log(1-x^k/k))/(1-x)))
%Y A356406 Cf. A308345, A356009, A356010, A356407, A356408.
%K A356406 nonn
%O A356406 1,2
%A A356406 _Seiichi Manyama_, Aug 05 2022