A191482 Number of n X n symmetric binary matrices with each 1 adjacent to no more than 6 king-move neighboring 1s

2, 8, 61, 932, 28310, 1702795, 202939372, 47927020569, 22429704522082, 20801275290690832, 38227523793468047029, 139214024121151998219523, 1004640378392088270863934462, 14366768178214114259445967952070

Offset

1,1

Links

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

Example

Some solutions for n=4
..0..1..0..0....1..1..0..1....1..0..0..0....1..0..1..0....1..1..1..0
..1..0..1..1....1..1..1..0....0..0..1..1....0..0..1..1....1..1..0..1
..0..1..1..0....0..1..0..1....0..1..1..1....1..1..1..1....1..0..1..0
..0..1..0..0....1..0..1..1....0..1..1..0....0..1..1..0....0..1..0..0

Crossrefs

Sequence in context: A085657 A005215 A058862 * A140722 A327078 A332779

Adjacent sequences: A191479 A191480 A191481 * A191483 A191484 A191485

Keyword

nonn

Author

R. H. Hardin Jun 03 2011

Status

approved