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 A333734 #8 Oct 15 2024 00:02:12 %S A333734 1,1,2,5,43,1856,1217727,8597641912,646296747486387, %T A333734 535435113671568180963,5081029530811947425598907884, %U A333734 570680215340337514993573217774604779,779646755088025699677478853259568262608053838 %N A333734 Number of non-isomorphic n X n nonnegative integer matrices with all row and column sums equal to n up to permutations of rows and columns. %e A333734 The a(2) = 2 matrices are: %e A333734 [1 1] [2 0] %e A333734 [1 1] [0 2] %e A333734 . %e A333734 The a(3) = 5 matrices are: %e A333734 [1 1 1] [2 1 0] [2 1 0] [3 0 0] [3 0 0] %e A333734 [1 1 1] [1 1 1] [0 2 1] [0 2 1] [0 3 0] %e A333734 [1 1 1] [0 1 2] [1 0 2] [0 1 2] [0 0 3] %Y A333734 Main diagonal of A333733 and A377060. %Y A333734 Cf. A110058. %K A333734 nonn,more %O A333734 0,3 %A A333734 _Andrew Howroyd_, Apr 04 2020 %E A333734 a(11)-a(12) from _Andrew Howroyd_, Oct 14 2024