A190533 Number of (n+2)X(n+2) symmetric binary matrices without the pattern 0 1 1 vertically or horizontally

42, 332, 3660, 59408, 1405148, 49455712, 2586803564, 202549927174, 23737296725976, 4174330956088592, 1101527208080551428, 436589349514722980996, 259916332325245438667936

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..19

Example

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

Crossrefs

Sequence in context: A252937 A033277 A362103 * A190602 A134386 A200875

Adjacent sequences: A190530 A190531 A190532 * A190534 A190535 A190536

Keyword

nonn

Author

R. H. Hardin May 12 2011

Status

approved