A155270 Number of ways to place zero or more nonadjacent 1,1 2,1 3,1 3,2 4,0 4,1 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 25, 55, 241, 1393, 11002, 99401, 1043872, 13453795, 226833102, 4837029282, 127481277055

Offset

4,2

Links

Table of n, a(n) for n=4..16.

Example

Maximal 12 X 12 X 12 example
..............0
.............0.0
............0.0.0
...........0.1.0.1
..........1.1.0.0.1
.........0.1.0.0.1.0
........0.1.0.0.1.1.0
.......0.0.1.0.1.0.0.0
......1.0.0.0.0.0.1.0.1
.....0.1.0.1.1.1.1.0.1.0
....0.1.1.0.0.1.0.0.1.1.0
...0.0.0.1.1.0.0.1.1.0.0.0

Crossrefs

Sequence in context: A155298 A155292 A155276 * A155256 A155230 A155231

Adjacent sequences: A155267 A155268 A155269 * A155271 A155272 A155273

Keyword

nonn

Author

R. H. Hardin, Jan 22 2009

Status

approved