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 A106243 #14 Aug 05 2019 17:46:18 %S A106243 1,0,1,1,1,0,0,2,3,3,13,13,11,6,0,0,26,50,67,73,73,505,505,479,403, %T A106243 286,146,0,0,1010,1994,2876,3565,3997,4143,4143,39313,39313,38303, %U A106243 35299,30429,23988,16426,8286,0,0,78626,156242,229844,295572,349989,390403 %N A106243 Triangle read by rows from left to right. However, triangle is constructed in the boustrophedon way, reading alternately right to left and left to right. Top entry is 1. In all later rows, initial entry is 0, other entries are sum of previous entry in that row plus sum of two entries above it in previous row. %e A106243 Triangle begins: %e A106243 1 %e A106243 0 1 %e A106243 1 1 0 %e A106243 0 2 3 3 %e A106243 13 13 11 6 0 (e.g., 11 = 6 + 3 + 2) %e A106243 0 26 50 67 73 73 (e.g., 50 = 26 + 13 + 11) %p A106243 T[0,0]:=1: for n from 0 to 12 do T[n,-1]:=0 od: for n from 0 to 12 do T[n,n+1]:=0 od: for n from 1 by 2 to 12 do T[n,0]:=0: for k from 1 to n do T[n,k]:=T[n,k-1]+T[n-1,k]+T[n-1,k-1] od: T[n+1,n+1]:=0: for j from 1 to n+1 do T[n+1,n+1-j]:=T[n+1,n+2-j]+T[n,n+1-j]+T[n,n-j] od: od: for n from 0 to 9 do seq(T[n,k],k=0..n) od; # yields sequence in triangular form; not necessarily the best Maple program # _Emeric Deutsch_, Aug 03 2005 %Y A106243 Cf. A007318, A008280, A008281, A106242. The row ends give A059294. Row sums give A106327. %K A106243 nonn,tabl,easy %O A106243 0,8 %A A106243 _N. J. A. Sloane_, May 29 2005 %E A106243 More terms from _Emeric Deutsch_, Aug 03 2005