A331707 Number of nonnegative integer matrices with 3 distinct columns and any number of distinct nonzero rows with column sums n and columns in decreasing lexicographic order.

0, 1, 46, 1900, 73028, 2448599, 75497242, 2339274204, 69674762468, 1979828352817, 54476556180342, 1451352388018928, 37417987990316376, 936855054326483475, 22833066202591181758, 542259452432969505704, 12569324678536063256324, 284784345516356806067001, 6313245421002223574950650

Offset: 0

Author

Andrew Howroyd, Jan 25 2020

Keywords

• nonn

Comments

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

Examples

			The a(1) = 1 matrix is:
  [1 0 0]
  [0 1 0]
  [0 0 1]
		

Crossrefs

Column k=3 of A331570.

Cf. A331706.