

A326342


Number of n X n binary matrices with total support.


2




OFFSET

1,2


COMMENTS

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)]


LINKS



EXAMPLE

For n = 2 the a(2) = 3 matrices are:
[1 1] [1 0] [0 1]
[1 1], [0 1], [1 0].


CROSSREFS

A326343 counts only the inequivalent matrices.


KEYWORD

nonn,more


AUTHOR



STATUS

approved



