A155280 Number of ways to place zero or more nonadjacent 1,1 2,1 3,1 4,0 4,1 5,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 168, 718, 3579, 25444, 183468, 1516279, 16609058, 206526436, 3056554913, 55553877912

Offset

5,2

Links

Table of n, a(n) for n=5..18.

Example

Maximal 12 X 12 X 12 example
..............0
.............1.0
............0.1.1
...........0.1.0.0
..........0.1.0.1.0
.........0.1.0.0.1.0
........0.0.0.0.0.1.0
.......1.0.0.0.1.0.1.1
......0.1.1.0.1.0.1.0.0
.....0.1.0.0.1.0.0.0.0.1
....0.1.0.1.1.0.1.1.1.1.0
...0.1.0.0.0.1.0.0.0.0.1.0

Crossrefs

Sequence in context: A155319 A155318 A367649 * A155365 A155364 A155332

Adjacent sequences: A155277 A155278 A155279 * A155281 A155282 A155283

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved