A155230 Number of ways to place zero or more nonadjacent 1,0 2,0 2,1 2,2 3,0 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 25, 55, 249, 2622, 27709, 246241, 3322988, 74905084, 2082119083, 63776107886, 2604956304910, 150599199628251, 11318149143066683

Offset

3,2

Links

Table of n, a(n) for n=3..17.

Example

Maximal 13 X 13 X 13 example
...............0
..............0.0
.............0.0.0
............1.0.0.1
...........1.0.0.0.1
..........1.1.0.0.1.1
.........0.0.1.0.1.0.0
........0.1.0.0.0.0.1.0
.......1.1.0.1.1.1.0.1.1
......0.1.0.0.0.1.0.0.1.0
.....1.0.1.0.1.0.1.0.1.0.1
....0.1.0.0.0.1.0.0.0.0.1.0
...0.1.1.1.0.1.1.1.0.1.1.1.0

Crossrefs

Sequence in context: A155276 A155270 A155256 * A155231 A155261 A365444

Adjacent sequences: A155227 A155228 A155229 * A155231 A155232 A155233

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved