A331344 Number of nonnegative integer matrices with n distinct columns and any number of distinct nonzero rows with each column sum being 3 and rows in decreasing lexicographic order.

1, 2, 15, 317, 12586, 803764, 75603729, 9880078404, 1719511013708, 385900586669488, 108870763685147631, 37821200661333033093, 15903952714275755480410, 7978911737260660423782839, 4717171385049289138016854041, 3251403192784472823846341645000

Offset

0,2

Comments

The condition that the rows be in decreasing order is equivalent to considering nonequivalent matrices with distinct rows up to permutation of rows.

Links

Andrew Howroyd, Table of n, a(n) for n = 0..100

Crossrefs

Row n=3 of A331160.

Cf. A331196, A331316,

Sequence in context: A059167 A003025 A015200 * A030642 A365358 A297077

Adjacent sequences: A331341 A331342 A331343 * A331345 A331346 A331347

Keyword

nonn

Author

Andrew Howroyd, Jan 14 2020

Status

approved