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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
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

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

CROSSREFS

Column k=2 of A331485.

Sequence in context: A027990 A037520 A218836 * A052911 A126133 A186240

Adjacent sequences:  A331719 A331720 A331721 * A331723 A331724 A331725

KEYWORD

nonn

AUTHOR

Andrew Howroyd, Jan 31 2020

STATUS

approved

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Last modified April 5 00:43 EDT 2020. Contains 333238 sequences. (Running on oeis4.)