A155345 Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 3,1 4,1 5,2 6,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 52, 193, 781, 3781, 20901, 131341, 1017012, 9065243, 91925870

Offset

6,2

Links

Table of n, a(n) for n=6..17.

Example

Maximal 12 X 12 X 12 example
..............1
.............1.0
............0.1.0
...........0.1.0.0
..........0.1.0.0.0
.........0.0.1.0.0.1
........0.0.1.0.0.0.1
.......1.1.0.0.0.0.1.0
......0.0.1.1.1.0.0.1.0
.....1.1.0.0.0.1.1.0.1.0
....0.0.1.1.1.0.0.0.1.0.0
...0.0.0.0.0.1.1.0.0.1.0.0

Crossrefs

Sequence in context: A155423 A155347 A155385 * A155309 A155419 A155246

Adjacent sequences: A155342 A155343 A155344 * A155346 A155347 A155348

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved