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 A107652 #16 Jul 02 2023 07:00:35 %S A107652 1,0,0,0,1,0,0,0,0,0,0,1,2,1,0,0,0,0,0,0,0,0,4,8,10,8,4,0,0,0,0,0,0,0, %T A107652 0,0,0,34,68,94,104,94,68,34,0,0,0,0,0,0,0,0,0,0,0,0,496,992,1420, %U A107652 1712,1816,1712,1420,992,496,0,0,0,0,0,0,0,0,0,0,0,0,0,0 %N A107652 Triangle of numbers arising in enumeration of binary trees. %C A107652 Essentially the same triangle as in A008301, but with more zeros. %H A107652 Christiane Poupard, <a href="http://dx.doi.org/10.1016/S0195-6698(89)80009-5">Deux propriétés des arbres binaires ordonnés stricts</a>, Europ. J. Combin., Vol. 10 (1989), pp. 369-374. %Y A107652 Cf. A008301. Leading diagonal and row sums = (essentially) A107652. %K A107652 nonn,tabl,easy %O A107652 0,13 %A A107652 _N. J. A. Sloane_