A187621 Number of (n+1)X(n+1) 0..1 arrays with each 2X2 non-center subblock determinant nonzero and the array of 2X2 subblock determinants antisymmetric under 90 degree rotation.

10, 24, 2, 948, 36, 190972, 3020, 194618700, 929380, 1018751442652, 1744283776, 27189851221308572, 15262275217840

Offset: 1

Author

R. H. Hardin Mar 12 2011

Keywords

• nonn

Comments

Column 1 of A187624

Examples

			All solutions for 4X4
..1..1..0..1....1..0..1..1
..0..1..1..1....1..1..1..0
..1..1..1..0....0..1..1..1
..1..0..1..1....1..1..0..1