A187625 Number of 3X3 0..n arrays with each 2X2 non-center subblock determinant nonzero and the array of 2X2 subblock determinants antisymmetric under 90 degree rotation.

24, 446, 2924, 12104, 37448, 98014, 221640, 457632, 871712, 1562702, 2649632, 4329136, 6782660, 10323450, 15291860, 22111560, 31246860, 43422938, 59215112, 79658992, 105617736, 138251814, 178796912, 229108212, 290437464, 364933542

Offset: 1

Author

R. H. Hardin Mar 12 2011

Keywords

• nonn

Comments

Row 2 of A187624

Examples

			Some n=3 solutions for 3X3
..3..0..3....3..0..3....2..2..2....1..3..0....1..1..3....0..2..3....1..3..1
..3..3..0....0..2..3....1..3..1....1..0..1....1..0..1....1..0..1....2..3..2
..3..0..3....3..0..3....2..2..2....3..3..1....0..1..3....1..2..2....1..3..1
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..35