A187706 Number of 3X3 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.

128, 1489, 8272, 31461, 93476, 235773, 524284, 1062857, 1999212, 3541677, 5967404, 9648841, 15048584, 22766353, 33534080, 48248321, 67983232, 94042589, 127929948, 171449249, 226655576, 295941137, 382036240, 488090685, 617595596, 774557293

Offset: 1

Author

R. H. Hardin Mar 12 2011

Keywords

• nonn

Comments

Row 2 of A187705

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..33