A247597 Number of nonisomorphic binary n X n matrices with four 1's per column under row and column permutations.

1, 7, 132, 6178, 594203, 85820809, 16341829155, 3875736708590, 1112175913348040, 378860991866916370, 151006214911844288232, 69600017255860985666964, 36729204987785981237238642, 22003003913198378660826731007, 14851323097928973689736994569534

Offset: 4

Author

Marko Riedel, Sep 21 2014

Keywords

• nonn

Links

• Andrew Howroyd, Table of n, a(n) for n = 4..40
• StackExchange, How many arrays with crossed cells, order of rows/columns irrelevant, Dec 13 2013

Crossrefs

Column k=4 of A304942.

Cf. A247417, A247596, A247598.

Programs

Maple

seq(matrix_marks(n,4), n=3..15); # Using the uploaded program to A247417

PARI

\\ See A304942 for Blocks
a(n) = Blocks(n, n, 4); \\ Andrew Howroyd, May 24 2018

Extensions

Terms a(16) and beyond from Andrew Howroyd, May 24 2018