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A235457
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Number of non-equivalent (mod D_4) ways to arrange 6 points on an n X n square grid so that no three points are collinear.
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6
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1, 142, 4699, 77970, 672506, 4338248, 21167201, 85351595, 294664274, 911848844, 2528561187, 6501165477
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OFFSET
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3,2
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COMMENTS
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Without the restriction "non-equivalent (mod D_4)" the numbers are given by A194191, n >= 3.
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LINKS
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EXAMPLE
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There is a(3) = 1 way to place 6 points (X) on a 3 X 3 grid (without rotations and reflections):
. X X
X . X
X X .
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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