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 A169636 #4 Jul 22 2025 07:30:47
%S A169636 1,2,3,12,30,180,1260,5040,15120,151200,1663200
%N A169636 Number of permutations of A004001 sequence vectors:a(n)=Length[Permutations[Table[A004001[i], {i, 0, m}]]].
%F A169636 f(n) = f(f(n - 1)) + f(n - f(n - 1));
%F A169636 a(n)=Length[Permutations[Table[f(i), {i, 0, m}]]]
%t A169636 (*A004001*)
%t A169636 f[0] = 0; f[1] = 1; f[2] = 1;
%t A169636 f[n_] := f[n] = f[f[n - 1]] + f[n - f[n - 1]];
%t A169636 a[m_] := Length[Permutations[Table[f[i], {i, 0, m}]]];
%t A169636 b = Table[a[m], {m, 0, 10}]
%K A169636 nonn,uned
%O A169636 0,2
%A A169636 _Roger L. Bagula_, Apr 04 2010