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A333891 Number of nonequivalent n X n binary matrices with an equal number of ones in every row and column up to permutation of rows. 2
1, 2, 3, 4, 10, 48, 814, 35048, 4749917, 1991695464, 2744917591408, 12259363447566918, 187472413992607944600, 9519583446974164009046934, 1702816871202402787766029201942, 1029212386646920125804443494952269006, 2240000312861150532290111516186650669871299 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Andrew Howroyd, Table of n, a(n) for n = 0..20

EXAMPLE

The a(4) = 10 matrices are:

  [0 0 0 0]  [0 0 0 1]  [0 0 1 1]  [0 1 0 1]  [0 1 1 0]

  [0 0 0 0]  [0 0 1 0]  [0 0 1 1]  [0 1 0 1]  [0 1 1 0]

  [0 0 0 0]  [0 1 0 0]  [1 1 0 0]  [1 0 1 0]  [1 0 0 1]

  [0 0 0 0]  [1 0 0 0]  [1 1 0 0]  [1 0 1 0]  [1 0 0 1]

.

  [0 0 1 1]  [0 0 1 1]  [0 1 0 1]  [0 1 1 1]  [1 1 1 1]

  [0 1 1 0]  [0 1 0 1]  [0 1 1 0]  [1 0 1 1]  [1 1 1 1]

  [1 0 0 1]  [1 0 1 0]  [1 0 0 1]  [1 1 0 1]  [1 1 1 1]

  [1 1 0 0]  [1 1 0 0]  [1 0 1 0]  [1 1 1 0]  [1 1 1 1]

CROSSREFS

Row sums of A260340.

Sequence in context: A191224 A272523 A247204 * A270375 A049204 A045924

Adjacent sequences:  A333888 A333889 A333890 * A333892 A333893 A333894

KEYWORD

nonn

AUTHOR

Andrew Howroyd, Apr 18 2020

STATUS

approved

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Last modified August 8 11:31 EDT 2020. Contains 336298 sequences. (Running on oeis4.)