A221346 Number of 3Xn arrays of occupancy after each element stays put or moves to some horizontal, diagonal or antidiagonal neighbor, with no occupancy greater than 2

1, 137, 2856, 66077, 1534835, 36054361, 849482126, 20037479191, 472778990849, 11155734923302, 263229189709284, 6210988381194727, 146547761557950631, 3457733626802911867, 81582980136833112390, 1924884328527038591459

Offset

1,2

Comments

Row 3 of A221345

Links

R. H. Hardin, Table of n, a(n) for n = 1..18

Example

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

Crossrefs

Sequence in context: A215864 A190307 A094488 * A138348 A278175 A261973

Adjacent sequences: A221343 A221344 A221345 * A221347 A221348 A221349

Keyword

nonn

Author

R. H. Hardin Jan 11 2013

Status

approved