A183451 Number of n X n binary arrays with every 1 having exactly three king-move neighbors equal to 1.

1, 2, 5, 10, 60, 439, 2906, 36995, 739752, 16870217, 577680500, 39980454239, 4671945102210

Offset

1,2

Comments

Diagonal of A183456.

Links

Table of n, a(n) for n=1..13.

Example

Some solutions for 5X5
..1..1..0..1..1....0..0..0..0..0....1..1..0..0..0....0..0..0..1..1
..1..1..0..1..1....1..1..0..0..0....1..1..0..1..1....0..0..0..1..1
..0..0..0..0..0....1..1..0..0..0....0..0..0..1..1....0..0..0..0..0
..0..1..1..0..0....0..0..0..1..1....0..0..0..0..0....0..1..1..0..0
..0..1..1..0..0....0..0..0..1..1....0..0..0..0..0....0..1..1..0..0

Crossrefs

Sequence in context: A018503 A018535 A140304 * A018549 A053356 A018584

Adjacent sequences: A183448 A183449 A183450 * A183452 A183453 A183454

Keyword

nonn

Author

R. H. Hardin, Jan 05 2011

Status

approved