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 A235456 Number of non-equivalent (mod D_4) ways to arrange 5 points on an n X n square grid so that no three points are collinear. 6

%I

%S 5,217,3192,27041,149217,650566,2317137,7124316,19459757,48617666,

%T 111797647,241575473

%N Number of non-equivalent (mod D_4) ways to arrange 5 points on an n X n square grid so that no three points are collinear.

%C Column 5 of A235453.

%C Without the restriction "non-equivalent (mod D_4)" the numbers are given by A194190, n >= 3.

%e There are a(3) = 5 non-equivalent ways to place 5 points (X) on a 3 X 3 grid:

%e X . X X . X . X X X X . X . X

%e X . X X . . X . X X . . X X .

%e . X . . X X . X . . X X . X .

%Y Cf. A235453, A194190, A235454 (3 points), A235455 (4 points), A235457 (6 points), A235458 (7 points)

%K nonn,more

%O 3,1

%A _Heinrich Ludwig_, Jan 12 2014

%E a(13), a(14) from _Heinrich Ludwig_, Nov 16 2016

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Last modified December 5 14:49 EST 2021. Contains 349557 sequences. (Running on oeis4.)