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 A052317 #17 Nov 05 2021 09:47:57
%S A052317 1,1,1,6,56,730,12372,259574,6511920,190413234,6364960940,
%T A052317 239556803662,10028763883272,462366507311306,23282257730716740,
%U A052317 1271520006077859750,74865320814990626912,4727699146425478764898,318763676354643090937692,22856568223852002933212798
%N A052317 Number of labeled trees with n nodes and 2-colored internal (non-leaf) nodes.
%H A052317 <a href="/index/Tra#trees">Index entries for sequences related to trees</a>
%F A052317 E.g.f.: 1 + B(x) - x*B(x) - B(x)^2/2 where B(x) is e.g.f. of A052316.
%F A052317 a(n) ~ (1+LambertW(-exp(-1)/2))^(3/2) * n^(n-2) / (exp(n)*(-LambertW(-exp(-1)/2))^n). - _Vaclav Kotesovec_, Oct 05 2013
%t A052317 CoefficientList[Series[1+(1-x)*(-x-LambertW[-2*x*E^(-x)])-(-x-LambertW[-2*x*E^(-x)])^2/2, {x, 0, 20}], x]* Range[0, 20]! (* _Vaclav Kotesovec_, Oct 05 2013 *)
%Y A052317 Cf. A004113, A004114, A052316.
%K A052317 nonn
%O A052317 0,4
%A A052317 _Christian G. Bower_, Dec 15 1999