

A247417


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


5



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
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OFFSET

2,2


LINKS

Andrew Howroyd, Table of n, a(n) for n = 2..50
Marko Riedel, MAPLE Cycle Indices and Burnside Computation for NonIsomorphic 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



