

A235457


Number of nonequivalent (mod D_4) ways to arrange 6 points on an n X n square grid so that no three points are collinear.


6



1, 142, 4699, 77970, 672506, 4338248, 21167201, 85351595, 294664274, 911848844, 2528561187, 6501165477
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OFFSET

3,2


COMMENTS

Without the restriction "nonequivalent (mod D_4)" the numbers are given by A194191, n >= 3.


LINKS



EXAMPLE

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 .


CROSSREFS



KEYWORD

nonn,more


AUTHOR



EXTENSIONS



STATUS

approved



