A331718 Number of nonequivalent n-column binary matrices with 3 ones in every column and any number of distinct nonzero rows up to permutation of rows and columns.

1, 0, 0, 3, 23, 191, 2203, 31313

Offset

0,4

Links

Table of n, a(n) for n=0..7.

Example

The a(3) = 3 matrices are:
  [1, 1, 0]  [1, 1, 1]  [1, 1, 1]
  [1, 0, 1]  [1, 1, 0]  [1, 1, 0]
  [1, 0, 0]  [1, 0, 1]  [1, 0, 1]
  [0, 1, 1]  [0, 1, 0]  [0, 1, 1]
  [0, 1, 0]  [0, 0, 1]
  [0, 0, 1]

Crossrefs

Row n=3 of A331510.

Cf. A331717.

Sequence in context: A144479 A074579 A060880 * A093155 A370105 A241886

Adjacent sequences: A331715 A331716 A331717 * A331719 A331720 A331721

Keyword

nonn,more

Author

Andrew Howroyd, Feb 02 2020

Status

approved