A155290 Number of ways to place zero or more nonadjacent 1,0 1,1 2,1 3,1 4,2 5,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 25, 64, 265, 1577, 11987, 107928, 1180991, 15701569, 264954393, 5697447937, 151647215266

Offset

4,2

Links

Table of n, a(n) for n=4..16.

Example

Maximal 11 X 11 X 11 example
.............0
............0.1
...........0.1.1
..........1.1.0.0
.........1.0.0.1.1
........0.0.0.0.1.0
.......1.0.1.0.1.0.1
......1.0.0.1.0.1.0.1
.....0.1.0.1.0.1.0.1.0
....0.1.0.0.1.0.0.0.1.0
...0.1.1.0.1.1.0.0.1.1.0

Crossrefs

Sequence in context: A001845 A127765 A155305 * A056685 A299262 A001296

Adjacent sequences: A155287 A155288 A155289 * A155291 A155292 A155293

Keyword

nonn

Author

R. H. Hardin, Jan 22 2009

Status

approved