A155239 Number of ways to place zero or more nonadjacent 1,1 2,1 3,0 3,1 4,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 144, 940, 6913, 44442, 383165, 4775804, 73750670, 1270986469, 26693174009, 724206936085, 24621385504435

Offset

4,2

Links

Table of n, a(n) for n=4..18.

Example

Maximal 8 X 8 X 8 example
..........0
.........0.1
........1.1.0
.......0.0.1.0
......0.1.0.1.0
.....0.1.0.0.0.1
....1.1.0.1.1.1.0
...0.0.1.0.0.0.1.0

Crossrefs

Sequence in context: A155325 A155255 A155251 * A217421 A155376 A155377

Adjacent sequences: A155236 A155237 A155238 * A155240 A155241 A155242

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved