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 A220823 #13 Sep 17 2018 15:42:19 %S A220823 3,6,28,156,948,6206,42504,301548,2195100,16307598,123128940, %T A220823 942125110,7289062320,56926578912,448186662992,3553364598786, %U A220823 28345260090444,227337020914322,1832102040838776,14828608892376288,120485979704314764,982422914174633154,8036158136627878572 %N A220823 Number of rooted gene trees with n leaves on the label set [3]. %H A220823 Andrew Howroyd, <a href="/A220823/b220823.txt">Table of n, a(n) for n = 1..200</a> %H A220823 V. P. Johnson, <a href="http://people.math.sc.edu/czabarka/Theses/JohnsonThesis.pdf">Enumeration Results on Leaf Labeled Trees</a>, Ph. D. Dissertation, Univ. Southern Calif., 2012. %Y A220823 Column 3 of A319254. %K A220823 nonn %O A220823 1,1 %A A220823 _N. J. A. Sloane_, Dec 22 2012 %E A220823 Terms a(11) and beyond from _Andrew Howroyd_, Sep 17 2018