A187707 Number of 4X4 0..n arrays with each 2X2 subblock off diagonal and antidiagonal nonsingular and the array of 2X2 subblock determinants antisymmetric about the diagonal and antidiagonal.

2, 72, 322, 1718, 2904, 9834, 13324, 31000, 49910, 84760, 98226, 211526, 234336, 325654, 454612, 691052, 742006, 1152832, 1224538, 1765938

Offset: 1

Author

R. H. Hardin Mar 12 2011

Keywords

• nonn

Comments

Row 3 of A187705

Examples

			Some n=3 solutions for 4X4
..1..1..0..0....1..3..0..0....0..0..1..1....0..3..1..2....0..2..0..0
..2..2..2..2....1..3..2..3....1..1..1..1....0..1..1..2....0..2..1..3
..2..1..1..0....3..3..2..0....0..1..1..2....2..2..2..2....1..2..1..1
..0..0..2..0....0..0..2..0....0..1..0..0....0..0..1..1....1..2..2..2