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 A089940 #4 Jun 02 2025 00:16:53 %S A089940 1,1,1,2,1,1,3,4,1,1,6,5,6,1,1,10,15,7,8,1,1,20,21,28,9,10,1,1,35,56, %T A089940 36,45,11,12,1,1,70,84,120,55,66,13,14,1,1,126,210,165,220,78,91,15, %U A089940 16,1,1,252,330,495,286,364,105,120,17,18,1,1,462,792,715,1001,455,560,136,153 %N A089940 Triangle read by rows: T(n,k)=binomial(n+k,floor((n-k)/2)). %Y A089940 Columns include A001405, A037955, A037956, A037957. Row sums are A089941. %K A089940 easy,nonn,tabl %O A089940 0,4 %A A089940 _Paul Barry_, Nov 16 2003