A187698 Number of (n+1)X(n+1) 0..3 arrays with each 2X2 subblock determinant nonzero and the array of 2X2 subblock determinants symmetric under horizontal and vertical reflection

192, 74, 87258, 22738, 1089964504

Offset

1,1

Comments

Column 3 of A187699

Links

Table of n, a(n) for n=1..5.

Example

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

Crossrefs

Sequence in context: A118095 A155843 A187527 * A206343 A206336 A206335

Adjacent sequences: A187695 A187696 A187697 * A187699 A187700 A187701

Keyword

nonn

Author

R. H. Hardin Mar 12 2011

Status

approved