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 A038061 #17 Feb 14 2017 11:07:38
%S A038061 3,18,243,5184,151875,5668704,257298363,13759414272,847288609443,
%T A038061 59049000000000,4594736955793347,394865111526801408,
%U A038061 37144672966729275363,3796313155316599873536,418886580596209716796875
%N A038061 a(n) = 3^n*n^(n-1).
%C A038061 Labeled rooted trees with 3-colored nodes.
%H A038061 <a href="/index/Ro#rooted">Index entries for sequences related to rooted trees</a>
%F A038061 E.g.f. B(3x) where B(x) is e.g.f. of A000169.
%p A038061 A038061:=n->3^n*n^(n-1): seq(A038061(n), n=1..20); # _Wesley Ivan Hurt_, Feb 13 2017
%t A038061 Table[3^n n^(n-1),{n,20}] (* _Harvey P. Dale_, Aug 24 2012 *)
%Y A038061 Cf. A000169, A038055-A038062.
%K A038061 nonn
%O A038061 1,1
%A A038061 _Christian G. Bower_, Jan 04 1999
%E A038061 New description from _Vladeta Jovovic_, Mar 08 2003