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 A370605 #8 Feb 23 2024 11:02:47 %S A370605 1,3,4,11,6,72,8,499,850,4988,12,142232,14,949392,7385394,26739587,18, %T A370605 1462302432,20,21233776156,253684768502,151243121780,24, %U A370605 104533367794192,25973364296906,102776106948752,26798029481115778,95394359150584904,30 %N A370605 a(n) = n! * Sum_{d|n} 1/((d-1)! * (n/d)!^d). %F A370605 If p is prime, a(p) = 1 + p. %F A370605 E.g.f.: Sum_{k>0} x^k/k! * exp(x^k/k!). %o A370605 (PARI) a(n) = n!*sumdiv(n, d, 1/((d-1)!*(n/d)!^d)); %o A370605 (PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(sum(k=1, N, x^k/k!*exp(x^k/k!)))) %Y A370605 Cf. A370581. %K A370605 nonn %O A370605 1,2 %A A370605 _Seiichi Manyama_, Feb 23 2024