A155376 Number of ways to place zero or more nonadjacent 1,1 2,0 2,1 3,1 3,2 4,1 5,1 6,1 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 153, 637, 2307, 11243, 74510, 497944, 3748694, 35838488, 378887007, 4442870787

Offset

6,2

Links

Table of n, a(n) for n=6..19.

Example

Maximal 10 X 10 X 10 example
............0
...........1.0
..........0.1.0
.........0.0.1.0
........0.1.0.1.1
.......1.1.0.1.1.0
......0.1.1.0.0.1.0
.....0.1.0.0.1.0.0.0
....0.1.0.1.1.1.1.1.1
...0.1.0.0.0.1.0.0.0.0

Crossrefs

Sequence in context: A155251 A155239 A217421 * A155377 A155227 A155319

Adjacent sequences: A155373 A155374 A155375 * A155377 A155378 A155379

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved