A155224 Number of ways to place zero or more nonadjacent 1,0 1,1 2,0 3,1 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 4, 13, 28, 111, 977, 7280, 55365, 714096, 13471597, 269297226, 6772718447, 245090678582, 11547321954885, 661077498433706, 49292298477002834, 4904773608293842400

Offset

2,2

Comments

Same series for 0,0 1,0 1,1 2,0 2,1 polyhexes.

Links

Table of n, a(n) for n=2..18.

Example

Maximal 9 X 9 X 9 example
...........0
..........1.1
.........1.0.1
........0.0.0.0
.......0.1.0.1.0
......0.0.1.1.0.0
.....1.0.0.0.0.0.1
....0.1.0.1.1.0.1.0
...1.1.0.1.0.1.0.1.1

Crossrefs

Sequence in context: A155413 A155326 A155257 * A155238 A155320 A155279

Adjacent sequences: A155221 A155222 A155223 * A155225 A155226 A155227

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved