A331720 Number of nonequivalent binary matrices with 4 columns and any number of nonzero rows with n ones in every column up to permutation of rows and columns.

1, 5, 23, 93, 332, 1062, 3117, 8399, 21051, 49451, 109698, 231230, 465900, 901425, 1681989, 3037536

Offset

0,2

Links

Table of n, a(n) for n=0..15.

Example

The a(1) = 5 matrices are:
  [1 0 0 0]  [1 1 0 0]  [1 1 1 0]  [1 1 0 0]  [1 1 1 1]
  [0 1 0 0]  [0 0 1 0]  [0 0 0 1]  [0 0 1 1]
  [0 0 1 0]  [0 0 0 1]
  [0 0 0 1]

Crossrefs

Column k=4 of A331461.

Sequence in context: A362764 A283224 A178834 * A327973 A255457 A146013

Adjacent sequences: A331717 A331718 A331719 * A331721 A331722 A331723

Keyword

nonn,more

Author

Andrew Howroyd, Jan 31 2020

Status

approved