A187529 Number of 3X3 0..n arrays with each 2X2 subblock determinant nonzero and the array of 2X2 subblock determinants symmetric under 90 degree rotation.

0, 8, 74, 280, 784, 1970, 3580, 6946, 11726, 19100, 27672, 44092, 58988, 83340, 116344, 156470, 193434, 262028, 316330, 414216, 517530, 629058, 735548, 935702, 1100836, 1299196, 1530340, 1835766, 2068728, 2511536, 2794280, 3249058, 3723336

Offset: 1

Author

R. H. Hardin Mar 10 2011

Keywords

• nonn

Comments

Row 2 of A187528

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..36