A190341 Number of (n+1)X(n+1) symmetric binary matrices without the pattern 1 1 diagonally or antidiagonally

3, 9, 40, 273, 2727, 41520, 944307, 32403123, 1667310336, 129124175985, 15018894671481, 2626862719652352, 690390044069042835, 272767004386769371833, 161965593156881121867648

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..25

Example

Some solutions for 3X3
..0..0..0....1..0..0....0..0..0....0..0..1....0..0..1....1..0..1....1..0..1
..0..0..0....0..0..0....0..1..0....0..0..0....0..0..0....0..0..0....0..0..0
..0..0..0....0..0..0....0..0..0....1..0..1....1..0..0....1..0..1....1..0..0

Crossrefs

Sequence in context: A020092 A346753 A233533 * A222669 A179088 A027893

Adjacent sequences: A190338 A190339 A190340 * A190342 A190343 A190344

Keyword

nonn

Author

R. H. Hardin May 09 2011

Status

approved