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 A287141 #28 Dec 26 2021 23:34:15 %S A287141 0,0,1,1,2,5,12,25,64,166,405,1050,2763,7239,19190,51457,138538, %T A287141 374972,1020943,2792183,7666358,21126905,58422650,162052566,450742451, %U A287141 1256974690,3513731861,9843728012,27633400879,77721141911,218984204904,618021576627,1746906189740,4945026080426,14017220713131 %N A287141 Numbers of closed affine (a.k.a. BCK) lambda terms of natural size n. %H A287141 Pierre Lescanne, <a href="/A287141/b287141.txt">Table of n, a(n) for n = 0..100</a> %H A287141 Pierre Lescanne, <a href="https://arxiv.org/abs/1702.03085">Quantitative aspects of linear and affine closed lambda term</a>, arXiv:1702.03085 [cs.DM], 2017. %Y A287141 Cf. A281270, A275057. %K A287141 nonn %O A287141 0,5 %A A287141 _Pierre Lescanne_, May 20 2017