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A326342
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Number of n X n binary matrices with total support.
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2
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OFFSET
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1,2
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COMMENTS
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A nonnegative matrix has total support if it is nonzero and for every positive entry there exists a permutation of the columns such that the positive entry is a diagonal entry afterwards and all diagonal entries are positive afterwards.
Number of n X n binary matrices generated by applying the sign function on the entries of a doubly stochastic n X n matrix. - [R. Sinkhorn and P. Knopp (1967)]
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LINKS
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EXAMPLE
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For n = 2 the a(2) = 3 matrices are:
[1 1] [1 0] [0 1]
[1 1], [0 1], [1 0].
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CROSSREFS
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A326343 counts only the inequivalent matrices.
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KEYWORD
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nonn,more
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AUTHOR
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STATUS
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approved
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