A155247 Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 3,2 4,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 43, 187, 1189, 7473, 55294, 540344, 6609867, 96912191, 1762761733, 39425343425, 1088609961302

Offset

4,2

Links

Table of n, a(n) for n=4..17.

Example

Maximal 11 X 11 X 11 example
.............0
............0.0
...........0.1.1
..........0.1.0.0
.........1.1.0.0.0
........0.0.0.0.0.0
.......1.0.1.0.1.0.1
......0.1.0.1.0.1.0.1
.....0.1.0.1.0.1.0.1.0
....0.1.0.1.0.1.0.1.0.0
...0.0.1.0.1.0.1.0.1.0.0

Crossrefs

Sequence in context: A155312 A155351 A155430 * A113927 A155399 A330854

Adjacent sequences: A155244 A155245 A155246 * A155248 A155249 A155250

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved