A221854 Number of 3Xn arrays of occupancy after each element stays put or moves to some horizontal, diagonal or antidiagonal neighbor, without consecutive moves in the same direction

1, 306, 10085, 465305, 19159028, 811781250, 34109464173, 1436352539452, 60446151885851, 2544184795092968

Offset

1,2

Comments

Row 3 of A221852

Links

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

Example

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

Crossrefs

Sequence in context: A172966 A223073 A064257 * A221724 A023908 A035843

Adjacent sequences: A221851 A221852 A221853 * A221855 A221856 A221857

Keyword

nonn

Author

R. H. Hardin Jan 27 2013

Status

approved