A155333 Number of ways to place zero or more nonadjacent 0,0 1,0 2,0 3,0 4,1 5,2 6,3 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 70, 241, 813, 4400, 23369, 158297, 1249218, 10771936, 115482200

Offset

6,2

Links

Table of n, a(n) for n=6..17.

Example

Maximal 12 X 12 X 12 example
..............0
.............0.1
............0.0.1
...........0.0.0.1
..........0.0.0.0.1
.........1.0.0.0.1.0
........1.0.0.0.1.0.1
.......1.0.0.0.1.0.1.0
......1.0.0.0.0.0.1.0.1
.....0.1.0.1.1.1.1.0.1.0
....0.0.1.0.0.0.0.0.1.0.0
...0.0.0.1.0.1.1.1.1.0.0.0

Crossrefs

Sequence in context: A228026 A122484 A155242 * A155296 A155463 A318483

Adjacent sequences: A155330 A155331 A155332 * A155334 A155335 A155336

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved