A331645 Number of nonnegative integer matrices with n columns and any number of distinct nonzero rows with column sums 3.

1, 3, 87, 11655, 4498191, 3611504823, 5192498314767, 12172382140406295, 43436006002867938351, 224018914608150321575223, 1603777845822934662938327247, 15430102163147097295950086754135, 194280602846166109497542618768659311, 3131120528310366432743101620841328437623

Offset: 0

Author

Andrew Howroyd, Jan 23 2020

Keywords

• nonn

Examples

			The a(1) = 3 matrices are:
   [2]  [1]  [3]
   [1]  [2]
		

Links

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

Crossrefs

Row n=3 of A331568.

Cf. A331644.