A221729 Number of 3Xn arrays of occupancy after each element stays put or moves to some horizontal, diagonal or antidiagonal neighbor, with every occupancy equal to zero or two

0, 16, 0, 540, 0, 22180, 0, 911081, 0, 37357844, 0, 1530451369, 0, 62678117602, 0, 2566608259733, 0, 105095354454990, 0, 4303284726664321, 0, 176203240002820998, 0, 7214839389152381265, 0, 295419432979789366510, 0, 12096265452242634926017

Offset

1,2

Comments

Row 3 of A221728

Links

R. H. Hardin, Table of n, a(n) for n = 1..32

Example

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

Crossrefs

Sequence in context: A002607 A221404 A221726 * A219950 A221271 A198804

Adjacent sequences: A221726 A221727 A221728 * A221730 A221731 A221732

Keyword

nonn

Author

R. H. Hardin Jan 22 2013

Status

approved