A331721 Number of nonequivalent n-column nonnegative integer matrices with column sums 4 and any number of nonzero rows up to permutation of rows and columns.

1, 5, 66, 1338, 43686, 2142277, 149056260, 13991691663, 1705750869937, 262268740077763, 49694977078927305, 11388565848749818055, 3107918736854019004136, 996840601151518793573156, 371595543159269706775806375, 159437222426663041455988930042, 78072200940916732097886063687252

Offset

0,2

Links

Table of n, a(n) for n=0..16.

Crossrefs

Row n=4 of A331485.

Sequence in context: A279463 A361409 A367837 * A367847 A209935 A156597

Adjacent sequences: A331718 A331719 A331720 * A331722 A331723 A331724

Keyword

nonn

Author

Andrew Howroyd, Jan 31 2020

Status

approved