A247417 Number of nonisomorphic binary n X n matrices with two 1's per column under row and column permutations.

1, 3, 11, 35, 132, 471, 1806, 7042, 28494, 118662, 510517, 2262738, 10337474, 48625631, 235357470, 1171163995, 5986424739, 31403695142, 168913667164, 930739116386, 5249162406890, 30275048671498, 178428441191289, 1073737691984694, 6592909590432719

Offset

2,2

Links

Andrew Howroyd, Table of n, a(n) for n = 2..50

Marko Riedel, MAPLE Cycle Indices and Burnside Computation for Non-Isomorphic N by N binary matrices with K entries per column under row and column permutation

StackExchange, How many arrays with crossed cells, order of rows/columns irrelevant, Dec 13 2013

Maple

Using the uploaded program the call is seq(matrix_marks(n, 2), n=3..15);

Prog

(PARI) \\ See A304942 for Blocks
a(n) = Blocks(n, n, 2); \\ Andrew Howroyd, May 24 2018

Crossrefs

Column k=2 of A304942.

Cf. A247596, A247597, A247598.

Sequence in context: A320087 A014335 A147474 * A222286 A119143 A119092

Adjacent sequences: A247414 A247415 A247416 * A247418 A247419 A247420

Keyword

nonn

Author

Marko Riedel, Sep 21 2014

Extensions

Terms a(17) and beyond from Andrew Howroyd, May 23 2018

Status

approved