A193118 Number of n X n symmetric 0..1 arrays with each element equal to the sum mod 2 of two of its horizontal and vertical neighbors

0, 1, 5, 39, 647, 21146, 1250105, 139314922, 29548707285, 11818077270598, 8900542771643288, 12649997383379784930, 33932210714032782401695, 171701849324595889268521428, 1639015389067019632170263988618

Offset

1,3

Links

R. H. Hardin, Table of n, a(n) for n = 1..20

Example

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

Crossrefs

Sequence in context: A322884 A352658 A221412 * A227636 A118991 A253920

Adjacent sequences: A193115 A193116 A193117 * A193119 A193120 A193121

Keyword

nonn

Author

R. H. Hardin Jul 16 2011

Status

approved