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.

1, 2, 7, 21, 66, 192, 565, 1579, 4348, 11582, 30205, 76736, 191120, 465920, 1115572, 2623885, 6074353, 13849021, 31137381, 69082779, 151390617, 327897173, 702426987, 1489108503, 3125821257, 6500086120, 13396645887, 27376083598, 55490121271, 111604327066, 222798559100

Offset

0,2

Links

Table of n, a(n) for n=0..30.

Zarif Ahsan, Xiran Liu, and Noah Rosenberg, Dissimilarity between a pair of draws from discrete probability vectors on finite sets of objects, Stanford Univ., 2023. See also arXiv:2410.00221, [math.CO], 2024, p. 5.

Crossrefs

Column k=2 of A331485.

Sequence in context: A027990 A037520 A218836 * A052911 A126133 A344500

Adjacent sequences: A331719 A331720 A331721 * A331723 A331724 A331725

Keyword

nonn

Author

Andrew Howroyd, Jan 31 2020

Status

approved