A155350 Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 3,2 4,2 5,2 6,3 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 43, 139, 529, 2779, 14903, 85160, 631076, 5508964, 55342292, 627643346

Offset

6,2

Links

Table of n, a(n) for n=6..18.

Example

Maximal 11 X 11 X 11 example
.............0
............0.0
...........0.0.0
..........0.0.0.1
.........0.1.1.1.0
........0.1.0.0.0.0
.......1.1.0.0.0.0.0
......0.0.0.1.0.0.0.1
.....0.1.1.1.0.1.1.1.0
....0.1.0.0.0.1.0.0.0.0
...1.1.0.0.1.1.0.0.0.0.0

Crossrefs

Sequence in context: A155336 A155427 A155403 * A155312 A155351 A155430

Adjacent sequences: A155347 A155348 A155349 * A155351 A155352 A155353

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved