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 A354845 #15 Jun 10 2022 11:08:03
%S A354845 1,3,7,49,121,2281,5041,134401,907201,13184641,39916801,3753509761,
%T A354845 6227020801,393409336321,7638997766401,160474477363201,
%U A354845 355687428096001,75792615407308801,121645100408832001,32459310892353945601,475723576423839744001,7306033564948620902401
%N A354845 a(n) = n! * Sum_{d|n} (n/d)^(d-1) / d!.
%H A354845 Seiichi Manyama, <a href="/A354845/b354845.txt">Table of n, a(n) for n = 1..447</a>
%F A354845 E.g.f.: Sum_{k>0} (exp(k * x^k) - 1)/k.
%F A354845 If p is prime, a(p) = 1 + p!.
%t A354845 a[n_] := n! * DivisorSum[n, (n/#)^(#-1)/#! &]; Array[a, 20] (* _Amiram Eldar_, Jun 08 2022 *)
%o A354845 (PARI) a(n) = n!*sumdiv(n, d, (n/d)^(d-1)/d!);
%o A354845 (PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(sum(k=1, N, (exp(k*x^k)-1)/k)))
%Y A354845 Cf. A087906, A327578, A354843.
%K A354845 nonn
%O A354845 1,2
%A A354845 _Seiichi Manyama_, Jun 08 2022