A240477 Number of n X n 0..1 arrays with no element equal to more than two horizontal or vertical neighbors, with new values 0..1 introduced in row major order

1, 8, 122, 4104, 306749, 50525365, 18384693920, 14778226489840, 26250644316475949, 103046989939554094945, 893993929233158179056828

Offset

1,2

Comments

Diagonal of A240484

Links

Table of n, a(n) for n=1..11.

Example

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

Crossrefs

Sequence in context: A361308 A359355 A349525 * A195247 A239755 A264408

Adjacent sequences: A240474 A240475 A240476 * A240478 A240479 A240480

Keyword

nonn

Author

R. H. Hardin, Apr 06 2014

Status

approved