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

0,2

Links

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

Example

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

Crossrefs

Row n=3 of A331568.

Cf. A331644.

Sequence in context: A230670 A232069 A172723 * A037112 A093748 A156737

Adjacent sequences: A331642 A331643 A331644 * A331646 A331647 A331648

Keyword

nonn

Author

Andrew Howroyd, Jan 23 2020

Status

approved