

A247158


Number of binary n X n matrices in which each row or column sum is at most n/2.


10



1, 1, 7, 34, 7343, 304186, 1709852332, 702998475376, 94473463102448047, 417235486592360297626, 1273060578884483984898786092, 63478599188626680785194983697744, 4243780803142765740205701619107014789924
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OFFSET

0,3


LINKS



EXAMPLE

a(2)=7 counts the following 2 X 2 matrices: 1 matrix with all zeros, 4 matrices where a 1 is at any of the four corners, and 2 matrices with 1's covering a diagonal.


CROSSREFS



KEYWORD

nonn


AUTHOR



EXTENSIONS



STATUS

approved



