A191479 Number of n X n symmetric binary matrices with each 1 adjacent to no more than 3 king-move neighboring 1s

2, 8, 42, 445, 8336, 273578, 16060725, 1663317205, 304789975903, 99026690954574, 56934478978072688, 57952230532394115913, 104449989219446543530778, 333288010626782017792094457, 1882901103468898454919475637369

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..17

Example

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

Crossrefs

Sequence in context: A153524 A153552 A295199 * A197935 A267619 A012917

Adjacent sequences: A191476 A191477 A191478 * A191480 A191481 A191482

Keyword

nonn

Author

R. H. Hardin Jun 03 2011

Status

approved