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 A367971 #10 Dec 07 2023 08:27:06
%S A367971 1,0,2,1,19,43,461,2350,22940,185313,1969105,20981585,255992617,
%T A367971 3300259584,46394533498,694535043925,11123040844947,189008829494295,
%U A367971 3402841007703469,64648146404160854,1293014652241452452,27152832827254344741,597366828915334031625
%N A367971 Expansion of e.g.f. exp(exp(-x) - 1)/(1 - x).
%F A367971 a(0) = 1; a(n) = Sum_{k=1..n} ((k-1)! + (-1)^k) * binomial(n-1,k-1) * a(n-k).
%F A367971 a(n) = n! * Sum_{k=0..n} (-1)^k * Bell(k)/k!, where Bell() is A000110.
%o A367971 (PARI) a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=sum(j=1, i, ((j-1)!+(-1)^j)*binomial(i-1, j-1)*v[i-j+1])); v;
%Y A367971 Cf. A101053, A367972.
%Y A367971 Cf. A000110, A087650, A186755.
%K A367971 nonn
%O A367971 0,3
%A A367971 _Seiichi Manyama_, Dec 06 2023