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 A246322 #15 Feb 13 2024 09:56:57 %S A246322 1,1,1,3,4,2,14,20,15,5,83,120,105,56,14,570,820,770,504,210,42,4318, %T A246322 6152,5985,4368,2310,792,132,35068,49448,49014,38136,23100,10296,3003, %U A246322 429 %N A246322 Triangle read by rows: T(n,k) = number of neutral planar lambda terms of size n with k free variables (n >= 0, 1 <= k <= n+1). %H A246322 Noam Zeilberger and Alain Giorgetti, <a href="http://arxiv.org/abs/1408.5028">A correspondence between rooted planar maps and normal planar lambda terms</a>, arXiv:1408.5028 [cs.LO], 2014. %e A246322 Triangle begins: %e A246322 1 %e A246322 1,1 %e A246322 3,4,2 %e A246322 14,20,15,5 %e A246322 83,120,105,56,14, %e A246322 570,820,770,504,210,42 %e A246322 4318,6152,5985,4368,2310,792,132 %e A246322 35068,49448,49014,38136,23100,10296,3003,429 %e A246322 ... %Y A246322 Cf. A000108, A001791, A220910, A246323. %K A246322 nonn,tabl,more %O A246322 0,4 %A A246322 _N. J. A. Sloane_, Aug 28 2014