A155246 Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 3,1 4,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 52, 214, 1321, 8505, 68818, 699514, 8734297, 133231510, 2556155829, 60226747541, 1749017832742

Offset

4,2

Links

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

Example

Maximal 11 X 11 X 11 example
.............1
............0.1
...........0.1.0
..........1.0.1.0
.........1.0.1.0.0
........0.1.0.0.0.0
.......0.1.0.0.0.0.0
......0.0.1.0.0.1.1.0
.....1.0.0.0.1.0.0.1.1
....0.1.1.0.0.1.1.0.0.1
...0.0.0.1.1.0.0.1.1.0.0

Crossrefs

Sequence in context: A155345 A155309 A155419 * A155414 A155374 A155272

Adjacent sequences: A155243 A155244 A155245 * A155247 A155248 A155249

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved