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 A047100 #5 Mar 30 2012 18:56:53
%S A047100 1,1,1,1,1,1,1,2,1,1,1,3,3,2,1,1,4,6,5,3,1,1,5,10,11,5,4,1,1,6,15,21,
%T A047100 16,5,5,1,1,7,21,36,37,21,10,6,1,1,8,28,57,73,58,31,16,7,1,1,9,36,85,
%U A047100 130,131,89,31,23,8,1,1,10,45,121,215,261,220
%N A047100 Array T read by diagonals: T(h,k)=number of paths consisting of steps from (0,0) to (h,k) such that each step has length 1 directed up or right and touches the line y=x/3 only at lattice points.
%e A047100 Diagonals (beginning on row 0): {1}; {1,1}; {1,1,1}; {1,2,1,1};...
%K A047100 nonn,tabl
%O A047100 0,8
%A A047100 _Clark Kimberling_