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 A331722 #12 Oct 12 2024 09:05:55 %S A331722 1,2,7,21,66,192,565,1579,4348,11582,30205,76736,191120,465920, %T A331722 1115572,2623885,6074353,13849021,31137381,69082779,151390617, %U A331722 327897173,702426987,1489108503,3125821257,6500086120,13396645887,27376083598,55490121271,111604327066,222798559100 %N A331722 Number of nonequivalent 2-column nonnegative integer matrices with column sums n and any number of nonzero rows up to permutation of rows and columns. %H A331722 Zarif Ahsan, Xiran Liu, and Noah Rosenberg, <a href="https://surim.stanford.edu/publications/combinatorics/dissimilarity-between-pair-draws-discrete-probability-vectors-finite">Dissimilarity between a pair of draws from discrete probability vectors on finite sets of objects</a>, Stanford Univ., 2023. See also <a href="https://arxiv.org/abs/2410.00221">arXiv:2410.00221</a>, [math.CO], 2024, p. 5. %Y A331722 Column k=2 of A331485. %K A331722 nonn %O A331722 0,2 %A A331722 _Andrew Howroyd_, Jan 31 2020