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 A385544 #14 Jul 03 2025 05:46:39
%S A385544 1,1,3,10,47,309,2846,37021,681653,17809832,661559047,34979604911,
%T A385544 2635492535328,283176079413813,43418520087991775,9505069880265893234,
%U A385544 2972315533856872301859,1328214006502208982129889,848461208731369665554869614,775048547251487987362405899361
%N A385544 G.f. A(x) satisfies A(x) = 1 + Sum_{k>=1} k * x^k * A(k*x).
%F A385544 a(0) = 1; a(n) = Sum_{k=0..n-1} (n-k)^(k+1) * a(k).
%F A385544 From _Vaclav Kotesovec_, Jul 03 2025: (Start)
%F A385544 a(n) ~ c * 3^(n*(n-1)/6), where
%F A385544 c = 151875.34106580399103962024875... if mod(n,3) = 0,
%F A385544 c = 151875.34107021815371382907842... if mod(n,3) = 1,
%F A385544 c = 151875.34106681673681179782608... if mod(n,3) = 2. (End)
%t A385544 a[0] = 1; a[n_] := a[n] = Sum[(n-k)^(k+1)*a[k], {k, 0, n-1}]; Table[a[n], {n, 0, 20}] (* _Vaclav Kotesovec_, Jul 03 2025 *)
%o A385544 (PARI) a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=sum(j=0, i-1, (i-j)^(j+1)*v[j+1])); v;
%Y A385544 Cf. A125282, A385548.
%K A385544 nonn,easy
%O A385544 0,3
%A A385544 _Seiichi Manyama_, Jul 03 2025