A187697 Number of (n+1)X(n+1) 0..2 arrays with each 2X2 subblock determinant nonzero and the array of 2X2 subblock determinants symmetric under horizontal and vertical reflection

50, 8, 7954, 1548, 15128848, 454640, 231192094416

Offset

1,1

Comments

Column 2 of A187699

Links

Table of n, a(n) for n=1..7.

Example

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

Crossrefs

Sequence in context: A036172 A242075 A187526 * A048178 A317619 A330848

Adjacent sequences: A187694 A187695 A187696 * A187698 A187699 A187700

Keyword

nonn

Author

R. H. Hardin Mar 12 2011

Status

approved