A155292 Number of ways to place zero or more nonadjacent 1,1 2,0 2,1 3,1 4,2 5,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 25, 55, 229, 1363, 11186, 97334, 991531, 12805571, 217664977, 4668424395, 121771975984

Offset

4,2

Links

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

Example

Maximal 10 X 10 X 10 example
............1
...........0.1
..........0.1.0
.........0.1.1.0
........0.0.0.1.0
.......1.1.0.0.0.1
......0.0.1.1.1.0.1
.....0.1.0.1.0.0.1.0
....1.1.1.0.0.0.1.1.0
...0.0.0.1.1.0.0.0.1.0

Crossrefs

Sequence in context: A155306 A155240 A155298 * A155276 A155270 A155256

Adjacent sequences: A155289 A155290 A155291 * A155293 A155294 A155295

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved