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 A038058 #18 Nov 02 2014 19:57:25
%S A038058 1,2,4,24,256,4000,82944,2151296,67108864,2448880128,102400000000,
%T A038058 4829076871168,253613523861504,14681377947951104,928873060356849664,
%U A038058 63772920000000000000,4722366482869645213696,375183514207494575620096
%N A038058 Number of labeled trees with 2-colored nodes.
%H A038058 Robert Israel, <a href="/A038058/b038058.txt">Table of n, a(n) for n = 0..321</a>
%H A038058 <a href="/index/Tra#trees">Index entries for sequences related to trees</a>
%F A038058 a(n) = A038057(n)/n = 2^n * n^(n-2) for n>=1. E.g.f. B(2*x) where B(x) is e.g.f. of A000272.
%p A038058 1, seq(2^n * n^(n-2), n=1..20); # _Robert Israel_, Nov 02 2014
%t A038058 nn = 17; f[x_] := Sum[n^(n - 2) x^n/n!, {n, 1, nn}];
%t A038058 Range[0, nn]! CoefficientList[Series[f[2 x] + 1, {x, 0, nn}], x] (* _Geoffrey Critzer_, Nov 02 2014 *)
%Y A038058 Cf. A000272, A038055-A038062.
%K A038058 nonn
%O A038058 0,2
%A A038058 _Christian G. Bower_, Jan 04 1999