A155231 Number of ways to place zero or more nonadjacent 1,1 2,1 2,2 3,0 3,1 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 25, 55, 259, 2433, 26055, 255284, 3429704, 71355614, 1963935839, 63893300754, 2652285259513, 148465098222315

Offset

3,2

Links

Table of n, a(n) for n=3..16.

Example

Maximal 13 X 13 X 13 example
...............0
..............1.0
.............1.1.1
............0.0.0.1
...........0.1.1.0.0
..........1.0.0.1.1.0
.........1.1.1.0.1.0.1
........0.0.0.1.0.0.1.1
.......0.1.1.0.0.1.1.0.0
......1.0.1.0.1.0.0.0.1.0
.....1.0.1.0.1.0.1.1.1.0.1
....0.1.0.1.0.1.0.1.0.0.1.1
...0.1.1.0.0.1.1.0.0.1.1.0.0

Crossrefs

Sequence in context: A155270 A155256 A155230 * A155261 A365444 A268239

Adjacent sequences: A155228 A155229 A155230 * A155232 A155233 A155234

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved