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A309984
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Number of n X n Latin squares with determinant 0, divided by 2.
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3
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OFFSET
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1,4
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LINKS
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EXAMPLE
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a(4)=16: There are 2*a(4) = 32 4 X 4 Latin squares with determinant = 0, one of which is
[1 4 3 2]
[4 1 2 3]
[3 2 1 4]
[2 3 4 1].
An example of a 6 X 6 Latin square with determinant = 0 is
[1 3 4 6 5 2]
[3 2 6 5 4 1]
[4 6 3 2 1 5]
[6 5 1 3 2 4]
[5 4 2 1 3 6]
[2 1 5 4 6 3].
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CROSSREFS
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KEYWORD
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nonn,more,hard
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AUTHOR
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STATUS
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approved
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