A155266 Number of ways to place zero or more nonadjacent 0,0 1,0 1,1 2,1 3,1 3,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 4, 13, 28, 70, 418, 3187, 20380, 144781, 1561781, 23475489, 388651137, 7313541265, 177385458253, 5624711721417, 217536953984714

Offset

3,2

Links

Table of n, a(n) for n=3..18.

Example

Maximal 11 X 11 X 11 example
.............0
............1.0
...........1.1.1
..........0.0.1.1
.........1.1.0.0.0
........0.1.0.1.1.0
.......0.1.1.0.1.1.1
......1.0.1.0.0.0.1.0
.....1.1.0.0.1.1.0.0.1
....0.1.0.1.1.1.0.1.1.1
...0.1.1.0.1.0.0.1.1.0.0

Crossrefs

Sequence in context: A372484 A112560 A009561 * A155413 A155326 A155257

Adjacent sequences: A155263 A155264 A155265 * A155267 A155268 A155269

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved