A155242 Number of ways to place zero or more nonadjacent 0,0 1,0 2,0 3,1 4,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 70, 235, 1578, 9621, 89416, 823589, 11073433, 160764354, 3227749885, 73045396627, 2178986476482

Offset

4,2

Links

Table of n, a(n) for n=4..17.

Example

Maximal 11 X 11 X 11 example
.............0
............0.0
...........1.1.1
..........0.0.0.1
.........1.1.1.0.1
........1.0.0.0.0.0
.......1.0.0.0.1.1.1
......0.0.0.0.0.0.0.1
.....1.0.1.1.1.0.1.0.1
....0.1.0.0.0.1.0.1.0.0
...0.0.1.1.1.0.1.0.1.1.1

Crossrefs

Sequence in context: A193643 A228026 A122484 * A155333 A155296 A155463

Adjacent sequences: A155239 A155240 A155241 * A155243 A155244 A155245

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved