A155317 Number of ways to place zero or more nonadjacent 1,1 2,0 2,1 2,2 3,1 4,1 4,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 82, 477, 3794, 21306, 111679, 917243, 11877917, 168569675, 2255808102, 36229000672, 799414704118, 22475315426770

Offset

4,2

Comments

Same series for 1,0 1,1 2,0 2,1 3,0 3,1 3,2 4,1 polyhexes.

Links

Table of n, a(n) for n=4..19.

Example

Maximal 9 X 9 X 9 example
...........0
..........1.1
.........0.1.0
........1.1.1.0
.......0.1.0.0.0
......0.0.0.0.1.1
.....1.0.1.0.0.1.0
....1.1.1.1.0.1.1.1
...0.0.1.0.0.0.0.1.0

Crossrefs

Sequence in context: A155408 A155358 A155353 * A237052 A155381 A155393

Adjacent sequences: A155314 A155315 A155316 * A155318 A155319 A155320

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved