A155352 Number of ways to place zero or more nonadjacent 1,0 1,1 2,0 2,2 3,0 4,1 4,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 61, 275, 2315, 14549, 65253, 367867, 3643355, 50258373, 656861493, 8054133067, 125882858619, 2726987375461, 73216488029301, 2108368359421323, 66596647574072923

Offset

4,2

Links

Table of n, a(n) for n=4..22.

Example

Maximal 9 X 9 X 9 example
...........0
..........1.1
.........0.0.1
........1.0.1.0
.......0.1.1.0.0
......0.0.0.0.1.1
.....1.0.1.0.1.0.1
....1.0.0.1.0.0.0.1
...0.1.1.1.0.0.1.1.0

Crossrefs

Sequence in context: A155340 A155409 A155406 * A155361 A155315 A155323

Adjacent sequences: A155349 A155350 A155351 * A155353 A155354 A155355

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved