A190536 Number of (n+2)X(n+2) symmetric binary matrices without the pattern 0 1 1 diagonally or antidiagonally

56, 528, 6600, 100980, 2117870, 61630794, 2607217770, 156166134300, 13953736838272, 1844353230617676, 367051670671034640, 109228902733245482050, 48925662805948380686500

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..18

Example

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

Crossrefs

Sequence in context: A219576 A219943 A204832 * A190070 A220930 A220209

Adjacent sequences: A190533 A190534 A190535 * A190537 A190538 A190539

Keyword

nonn

Author

R. H. Hardin May 12 2011

Status

approved