A187528 T(n,k)=Number of (n+1)X(n+1) 0..k arrays with each 2X2 subblock determinant nonzero and the array of 2X2 subblock determinants symmetric under 90 degree rotation.

6, 50, 0, 192, 8, 104, 512, 74, 3790, 0, 1126, 280, 35026, 1476, 9346, 2146, 784, 220802, 20554, 3607148, 0, 3760, 1970, 727842, 273102, 164460556, 296232, 4278774, 6112, 3580, 2327574, 992410

Offset: 1

Author

R. H. Hardin Mar 10 2011

Keywords

• nonn
• tabl

Comments

Table starts

.......6......50.......192....512...1126....2146.3760.6112

.......0.......8........74....280....784....1970.3580

.....104....3790.....35026.220802.727842.2327574

.......0....1476.....20554.273102.992410

....9346.3607148.164460556

.......0..296232

.4278774

Examples

			Some k=3 solutions for 5X5
..1..2..3..1..1....1..2..3..1..3....3..2..1..1..2....1..1..3..2..3
..0..2..2..0..2....0..3..3..0..3....1..0..1..2..2....3..0..3..3..3
..1..2..3..1..2....1..2..3..1..3....2..1..1..1..2....2..1..2..1..2
..1..0..1..1..0....2..1..3..2..3....2..2..1..0..1....3..3..3..0..3
..2..2..3..1..2....1..2..3..1..3....2..1..1..2..1....2..1..2..1..2
		

Crossrefs

Row 1 is A062801