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 A331723 #4 Feb 01 2020 14:38:17 %S A331723 1,3,23,162,1338,10585,82694,612700,4337251,29267424,189156449, %T A331723 1174258396,7027652401,40665520091,228144483468,1243885610116, %U A331723 6604645458105,34214740832064,173212883196153,858180731755508,4166502761618085,19845587224548144,92834956645809855,426901317803272329 %N A331723 Number of nonequivalent 3-column nonnegative integer matrices with column sums n and any number of nonzero rows up to permutation of rows and columns. %Y A331723 Column k=3 of A331485. %K A331723 nonn %O A331723 0,2 %A A331723 _Andrew Howroyd_, Jan 31 2020