A187634 Number of 4X4 0..n arrays with the array of 2X2 subblock determinants antisymmetric under horizontal and vertical reflection and each non-centerline 2X2 subblock nonsingular

24, 1648, 14044, 106892, 306320, 1848504, 3549080, 9810932, 19774644, 44235868, 65964188, 188874084, 261388436, 423186604, 755637740, 1198594384, 1533264084, 2755012728, 3428332204, 5907685880, 8225807516

Offset

1,1

Comments

Row 3 of A187633

Links

Table of n, a(n) for n=1..21.

Example

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

Crossrefs

Sequence in context: A019284 A333042 A112389 * A229430 A054777 A301392

Adjacent sequences: A187631 A187632 A187633 * A187635 A187636 A187637

Keyword

nonn

Author

R. H. Hardin Mar 12 2011

Status

approved