A155427 Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 3,2 4,2 5,3 6,4 7,4 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 43, 130, 466, 1972, 9920, 52566, 311924, 2236063, 18426118

Offset

7,2

Links

Table of n, a(n) for n=7..18.

Example

Maximal 10 X 10 X 10 example
............0
...........0.0
..........1.0.1
.........0.1.0.1
........0.1.0.1.0
.......0.1.0.1.0.0
......0.0.1.0.1.0.0
.....0.0.1.0.1.0.0.0
....0.0.1.0.1.0.0.0.0
...0.0.0.1.0.1.0.0.0.0

Crossrefs

Sequence in context: A155268 A124700 A155336 * A155403 A155350 A155312

Adjacent sequences: A155424 A155425 A155426 * A155428 A155429 A155430

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved