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

1,1

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

Links

Table of n, a(n) for n=1..32.

Example

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

Sequence in context: A046195 A305376 A024268 * A187699 A212232 A187670

Adjacent sequences: A187525 A187526 A187527 * A187529 A187530 A187531

Keyword

nonn,tabl

Author

R. H. Hardin, Mar 10 2011

Status

approved