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 A193488 #8 Feb 17 2018 21:11:59 %S A193488 0,0,0,0,1,1,6,11,42,92,294,720,2119,5460,15477,40989,114165,306980, %T A193488 848268,2301794,6341450,17308926,47659837,130628590,359924353, %U A193488 989642184,2730224431,7526539869,20795818601,57457010219 %N A193488 Number of rooted trees with n nodes and omega-valency 3. %C A193488 See A003120 for definitions. %H A193488 J.-C. Arditti, <a href="http://dx.doi.org/10.1016/0012-365X(73)90135-0">Dénombrement des arborescences dont le graphe de comparabilité est Hamiltonien</a>, Discrete Math., 5 (1973), 189-200. %Y A193488 Cf. A003120, A193487, A193489, A193490, A193491. %K A193488 nonn %O A193488 1,7 %A A193488 _N. J. A. Sloane_, Jul 27 2011