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 A354893 #16 Jun 11 2022 07:52:15
%S A354893 1,3,7,73,121,12361,5041,5308801,44452801,5681370241,39916801,
%T A354893 16800125569921,6227020801,35897693762810881,2134168822456070401,
%U A354893 190139202281277849601,355687428096001,3563095308471181273190401,121645100408832001
%N A354893 a(n) = n! * Sum_{d|n} d^(n - d) / (n/d)!.
%H A354893 Seiichi Manyama, <a href="/A354893/b354893.txt">Table of n, a(n) for n = 1..291</a>
%F A354893 E.g.f.: Sum_{k>0} (exp((k * x)^k) - 1)/k^k.
%F A354893 If p is prime, a(p) = 1 + p! = A038507(p).
%t A354893 a[n_] := n! * DivisorSum[n, #^(n - #)/(n/#)! &]; Array[a, 19] (* _Amiram Eldar_, Jun 10 2022 *)
%o A354893 (PARI) a(n) = n!*sumdiv(n, d, d^(n-d)/(n/d)!);
%o A354893 (PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(sum(k=1, N, (exp((k*x)^k)-1)/k^k)))
%Y A354893 Cf. A038507, A342628, A354845, A354891, A354892.
%K A354893 nonn
%O A354893 1,2
%A A354893 _Seiichi Manyama_, Jun 10 2022