A187622 Number of (n+1)X(n+1) 0..2 arrays with each 2X2 non-center subblock determinant nonzero and the array of 2X2 subblock determinants antisymmetric under 90 degree rotation.

31, 446, 60, 324452, 70548, 6090023738, 720252796

Offset: 1

Author

R. H. Hardin Mar 12 2011

Keywords

• nonn

Comments

Column 2 of A187624

Examples

			Some solutions for 4X4
..1..2..0..2....2..2..0..2....1..1..2..1....1..2..1..1....2..0..1..2
..0..2..1..2....0..2..2..2....2..1..1..1....1..1..1..2....1..2..2..0
..1..2..1..0....2..2..2..0....1..1..1..2....2..1..1..1....0..2..2..1
..1..0..1..2....2..0..2..2....1..2..1..1....1..1..2..1....2..1..0..2