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 A300127 #7 Feb 27 2018 03:40:27 %S A300127 0,1,2,3,10,34,98,339,1263,4626,18099,73782,306295,1319660,5844714, %T A300127 26481404,123172740 %N A300127 Number of Motzkin trees that are "typable closed terms". %C A300127 From the Bodini-Tarau paper: a Motzkin skeleton is called "typable" if "it exists at least one simply-typed closed lambda term having it as its skeleton". %H A300127 Olivier Bodini, Paul Tarau, <a href="https://arxiv.org/abs/1709.04302">On Uniquely Closable and Uniquely Typable Skeletons of Lambda Terms</a>, arXiv:1709.04302 [cs.PL], 2017. %Y A300127 Cf. A000108, A001006, A135501. %K A300127 nonn,more %O A300127 0,3 %A A300127 _Michael De Vlieger_, Feb 25 2018