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 A343263 #4 Apr 09 2021 22:09:49
%S A343263 1,1,1,2,22,301554,2493675105669492542968967478
%N A343263 a(0) = 1; a(n+1) = exp(-a(n)) * Sum_{k>=0} a(n)^k * k^n / k!.
%C A343263 The next term is too large to include.
%F A343263 a(0) = 1; a(n+1) = n! * [x^n] exp(a(n) * (exp(x) - 1)).
%F A343263 a(0) = 1; a(n+1) = Sum_{k=0..n} Stirling2(n,k) * a(n)^k.
%t A343263 a[0] = 1; a[n_] := a[n] = Sum[StirlingS2[n - 1, k] a[n - 1]^k, {k, 0, n - 1}]; Table[a[n], {n, 0, 6}]
%t A343263 a[0] = 1; a[n_] := a[n] = BellB[n - 1, a[n - 1]]; Table[a[n], {n, 0, 6}]
%Y A343263 Cf. A000110, A003659, A067691, A110386, A189233, A242817, A292860, A294373.
%K A343263 nonn
%O A343263 0,4
%A A343263 _Ilya Gutkovskiy_, Apr 09 2021