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 A354898 #23 Jul 11 2023 08:57:05
%S A354898 1,2,2,26,2,2582,2,268802,7348322,51120722,2,299332756802,2,
%T A354898 7157951760962,18701679546950402,613777679843328002,2,
%U A354898 3250742570192384467202,2,29411516073133093829529602,1146522800008167069616128002,4017001663590220290585602,2
%N A354898 a(n) = n! * Sum_{d|n} d^(n - d) / (d! * (n/d)!).
%H A354898 Robert Israel, <a href="/A354898/b354898.txt">Table of n, a(n) for n = 1..305</a>
%F A354898 E.g.f.: Sum_{k>0} (exp((k * x)^k) - 1)/(k^k * k!).
%F A354898 If p is prime, a(p) = 2.
%p A354898 f:= proc(n) local d; n! * add(d^(n-d)/(d! * (n/d)!), d = numtheory:-divisors(n)) end proc:
%p A354898 map(f, [$1..30]); # _Robert Israel_, Jul 10 2023
%t A354898 a[n_] := n! * DivisorSum[n, #^(n - #)/(#! * (n/#)!) &]; Array[a, 23] (* _Amiram Eldar_, Jun 11 2022 *)
%o A354898 (PARI) a(n) = n!*sumdiv(n, d, d^(n-d)/(d!*(n/d)!));
%o A354898 (PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(sum(k=1, N, (exp((k*x)^k)-1)/(k^k*k!))))
%Y A354898 Cf. A121860, A354845, A354891, A354893, A354897.
%K A354898 nonn
%O A354898 1,2
%A A354898 _Seiichi Manyama_, Jun 11 2022