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A331645
Number of nonnegative integer matrices with n columns and any number of distinct nonzero rows with column sums 3.
5
1, 3, 87, 11655, 4498191, 3611504823, 5192498314767, 12172382140406295, 43436006002867938351, 224018914608150321575223, 1603777845822934662938327247, 15430102163147097295950086754135, 194280602846166109497542618768659311, 3131120528310366432743101620841328437623
OFFSET
0,2
LINKS
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
KEYWORD
nonn
AUTHOR
Andrew Howroyd, Jan 23 2020
STATUS
approved