A155430 Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 3,2 4,3 5,4 6,5 7,5 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 43, 186, 802, 3291, 15504, 87663, 541655, 3932774, 33121807

Offset

7,2

Links

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

Example

Maximal 11 X 11 X 11 example
.............1
............0.1
...........0.1.0
..........0.1.0.1
.........0.1.0.1.0
........0.1.0.0.1.0
.......0.1.0.0.0.1.0
......0.0.1.0.0.0.1.0
.....0.0.0.0.0.1.0.1.0
....1.1.1.1.1.1.0.0.1.0
...1.0.0.0.0.0.0.0.1.0.0

Crossrefs

Sequence in context: A155350 A155312 A155351 * A155247 A113927 A155399

Adjacent sequences: A155427 A155428 A155429 * A155431 A155432 A155433

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved