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 A159768 #15 Sep 08 2023 01:22:37 %S A159768 1,1,2,5,14,41,124,385,1221,3939,12886,42648,142544,480459,1631287, %T A159768 5574073,19153815,66146259,229452587,799140681,2793373937,9796395680, %U A159768 34459558856,121548541383,429823475811,1523511450184,5411789548439 %N A159768 Number of n-leaf binary trees that do not contain (()(()(()((()())())))) as a subtree. %C A159768 By 'binary tree' we mean a rooted, ordered tree in which each vertex has either 0 or 2 children. %H A159768 CombOS - Combinatorial Object Server, <a href="http://combos.org/btree">Generate binary trees</a> %H A159768 Petr Gregor, Torsten Mütze, and Namrata, <a href="https://arxiv.org/abs/2306.08420">Combinatorial generation via permutation languages. VI. Binary trees</a>, arXiv:2306.08420 [cs.DM], 2023. %H A159768 Eric S. Rowland, <a href="http://arxiv.org/abs/0809.0488">Pattern avoidance in binary trees</a>, arXiv:0809.0488 [math.CO], 2008-2010. %F A159768 G.f. f(x) satisfies -x f(x)^3 + (x-1) x f(x)^2 + (x-1)^2 f(x) + (x-1) x = 0. %K A159768 nonn %O A159768 1,3 %A A159768 _Eric Rowland_, Apr 23 2009