A155318 Number of ways to place zero or more nonadjacent 1,0 1,1 2,1 2,2 3,1 4,1 5,1 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 162, 682, 2862, 19723, 141397, 1047499, 10569960, 123328797, 1599865270, 26321921029

Offset

5,2

Links

Table of n, a(n) for n=5..18.

Example

Maximal 9 X 9 X 9 example
...........0
..........1.1
.........0.1.1
........0.1.0.0
.......0.1.0.1.0
......0.1.0.0.1.0
.....1.0.0.0.0.1.0
....1.1.1.1.1.0.1.1
...0.1.0.0.0.0.1.1.0

Crossrefs

Sequence in context: A155377 A155227 A155319 * A367649 A155280 A155365

Adjacent sequences: A155315 A155316 A155317 * A155319 A155320 A155321

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved