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 A110855 #14 Jan 25 2020 18:26:49 %S A110855 1,0,0,0,1,0,0,1,1,0,0,1,2,1,0,0,1,4,4,1,0,0,1,8,11,8,1,0,0,1,16,28, %T A110855 28,16,1,0,0,1,32,71,87,71,32,1,0,0,1,64,184,266,266,184,64,1,0,0,1, %U A110855 128,491,823,952,823,491,128,1,0,0,1,256,1348,2598,3381,3381 %N A110855 Table T(n,k), n >= 0, k >= 0, product M*M^(T) where M is the lower triangular matrix in A048993 (Stirling2 numbers) and M^(T) denotes the transpose matrix of M, read by antidiagonals. %e A110855 Matrix M: %e A110855 1, 0, 0, 0, 0, 0, 0, 0, ... %e A110855 0, 1, 0, 0, 0, 0, 0, 0, ... %e A110855 0, 1, 1, 0, 0, 0, 0, 0, ... %e A110855 0, 1, 3, 1, 0, 0, 0, 0, ... %e A110855 0, 1, 7, 6, 1, 0, 0, 0, ... %e A110855 ... %e A110855 Matrix M^(T): %e A110855 1, 0, 0, 0, 0, 0, ... %e A110855 0, 1, 1, 1, 1, 1, ... %e A110855 0, 0, 1, 3, 7, 15, ... %e A110855 0, 0, 0, 1, 6, 25, ... %e A110855 0, 0, 0, 0, 1, 10, ... %e A110855 0, 0, 0, 0, 0, 1, ... %e A110855 ... %e A110855 Table begins: %e A110855 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ... %e A110855 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, %e A110855 0, 1, 2, 4, 8, 16, 32, 64, 128, ... %e A110855 0, 1, 4, 11, 28, 71, 184, 491, ... %e A110855 0, 1, 8, 28, 87, 266, 823, ... %e A110855 0, 1, 16, 71, 266, 952, ... %e A110855 0, 1, 32, 184, 823, ... %e A110855 0, 1, 64, 491, ... %e A110855 0, 1, 128, ... %e A110855 0, 1, ... %e A110855 0, ... %Y A110855 Diagonal sums: 1, 0, 1, 2, 4, 10, 29, 90, 295, ... see A000995. %Y A110855 Main diagonal: 1, 1, 2, 11, 87, 952, 13513, ... see A047797. %K A110855 nonn,tabl %O A110855 0,13 %A A110855 _Philippe Deléham_, Sep 17 2005