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.

5, 217, 3192, 27041, 149217, 650566, 2317137, 7124316, 19459757, 48617666, 111797647, 241575473

Offset: 3

Author

Heinrich Ludwig, Jan 12 2014

Keywords

• nonn
• more

Comments

Column 5 of A235453.

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

Examples

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

Crossrefs

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

Extensions

a(13), a(14) from Heinrich Ludwig, Nov 16 2016