A221872 Number of nX4 arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, without consecutive moves in the same direction

1, 1442, 109441, 14388224, 1572414124, 180850094177, 20435867743591, 2319666884003899, 262884477993316833

Offset

1,2

Comments

Column 4 of A221873

Links

Table of n, a(n) for n=1..9.

Example

Some solutions for n=3
..2..1..1..2....1..2..0..0....0..1..0..0....0..2..1..0....0..3..0..1
..1..1..0..1....0..3..0..3....2..3..1..1....0..3..1..1....0..4..3..0
..1..0..2..0....0..1..2..0....0..3..0..1....0..2..2..0....0..0..1..0

Crossrefs

Sequence in context: A178275 A220651 A252224 * A251842 A105417 A105416

Adjacent sequences: A221869 A221870 A221871 * A221873 A221874 A221875

Keyword

nonn

Author

R. H. Hardin Jan 28 2013

Status

approved