A240650 Number of n X n 0..1 arrays with no element equal to exactly one horizontal or vertical neighbor, with new values 0..1 introduced in row major order

1, 2, 9, 91, 2456, 184819, 37066859, 18940533171, 24272278810439, 77660940030730106

Offset

1,2

Comments

Diagonal of A240656

Links

Table of n, a(n) for n=1..10.

Example

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

Crossrefs

Sequence in context: A266293 A368840 A224323 * A356566 A365363 A011804

Adjacent sequences: A240647 A240648 A240649 * A240651 A240652 A240653

Keyword

nonn

Author

R. H. Hardin, Apr 09 2014

Status

approved