A191569 Number of n X n symmetric binary matrices with each 1 adjacent to no more than 1 knight-move neighboring 1.

2, 8, 34, 183, 2129, 33462, 770926, 26032324, 1354203171, 103491528931, 11756048816408, 2008909410467497, 510889483445894680, 194267241325094317359, 109588026470607538438518

Offset

1,1

Links

Table of n, a(n) for n=1..15.

Example

Some solutions for n=6
..1..0..0..0..0..0....1..0..1..1..0..0....1..0..0..0..0..0....0..1..0..0..1..1
..0..0..0..0..0..1....0..0..0..1..0..0....0..1..0..0..1..1....1..1..0..0..1..0
..0..0..1..0..0..0....1..0..0..0..0..0....0..0..0..0..1..1....0..0..0..0..1..1
..0..0..0..0..0..0....1..1..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..1..1....0..1..1..0..0..0....1..1..1..0..0..0
..0..1..0..0..0..1....0..0..0..0..1..0....0..1..1..0..0..1....1..0..1..0..0..1

Crossrefs

Sequence in context: A126328 A061370 A268558 * A229812 A346413 A383857

Adjacent sequences: A191566 A191567 A191568 * A191570 A191571 A191572

Keyword

nonn

Author

R. H. Hardin, Jun 06 2011

Status

approved