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

Author

Andrew Howroyd, Jan 14 2020

Keywords

• nonn

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,