A187696 Number of (n+1)X(n+1) 0..1 arrays with each 2X2 subblock determinant nonzero and the array of 2X2 subblock determinants symmetric under horizontal and vertical reflection

6, 0, 104, 0, 9350, 0, 4280018, 0, 9966761956, 0, 118224466422070, 0, 7149599148533804130, 0, 2205540801307910506482568, 0

Offset

1,1

Comments

Column 1 of A187699

Links

Table of n, a(n) for n=1..16.

Example

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

Crossrefs

Sequence in context: A072129 A085511 A187525 * A005212 A167028 A246137

Adjacent sequences: A187693 A187694 A187695 * A187697 A187698 A187699

Keyword

nonn

Author

R. H. Hardin Mar 12 2011

Status

approved