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%I #11 Nov 16 2016 15:51:28
%S 28,3385,134353,1958674,19929645,138586349,753795278,3356614240,
%T 13108210508,44374441652,137349454120
%N Number of non-equivalent (mod D_4) ways to arrange 7 points on an n X n square grid so that no three points are collinear.
%C Column 7 of A235453.
%C Without the restriction "non-equivalent (mod D_4)" the numbers are given by A194192, n >= 4.
%e There are a(4) = 28 non-equivalent ways to place 7 points (X) on a 4 X 4 grid. Example:
%e . X X .
%e . . . X
%e X . . X
%e X X . .
%Y Cf. A235453, A194192, A235454 (3 points), A235455 (4 points), A235456 (5 points), A235457 (6 points).
%K nonn,more
%O 4,1
%A _Heinrich Ludwig_, Jan 12 2014
%E a(13), a(14) from _Heinrich Ludwig_, Nov 16 2016