A155319 Number of ways to place zero or more nonadjacent 1,1 2,1 2,2 3,1 4,0 4,1 5,1 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 162, 682, 2796, 19279, 139378, 1039172, 10455828, 121464277, 1566433989, 25757470951

Offset

5,2

Links

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

Example

Maximal 12 X 12 X 12 example
..............0
.............1.0
............1.1.0
...........0.0.1.0
..........0.1.0.1.1
.........0.1.1.0.1.0
........0.1.0.0.0.0.0
.......1.1.0.1.0.0.1.0
......0.1.0.1.1.0.1.1.0
.....1.0.0.0.0.1.0.0.1.0
....1.1.1.1.1.0.1.1.0.1.1
...0.0.0.0.1.0.0.1.0.0.1.0

Crossrefs

Sequence in context: A155376 A155377 A155227 * A155318 A367649 A155280

Adjacent sequences: A155316 A155317 A155318 * A155320 A155321 A155322

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved