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 A175936 #9 May 09 2022 00:36:23
%S A175936 1,2,10,62,433,3262,25784,210892,1769793,15152252,131826824,
%T A175936 1162114368,10357863128,93183955872,845064072102,7717150002692,
%U A175936 70903816529979,654967192303546,6079243786794502,56668633625876866,530291242720187193
%N A175936 Number of lattice walks from (0,0) to (n,n) using steps S={(k,0),(0,k),(r,r)|0<k<=3,0<r<=2} which never go above the line y=x.
%Y A175936 Cf. A175934, A175935, A175937, A175939.
%K A175936 nonn
%O A175936 0,2
%A A175936 _Eric Werley_, Dec 06 2010