A155398 Number of ways to place zero or more nonadjacent 1,1 2,0 2,1 3,1 4,2 5,2 5,3 6,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 94, 343, 1447, 8149, 47996, 306243, 2223176, 19248076, 198155209, 2388609821, 33179404593

Offset

6,2

Links

Table of n, a(n) for n=6..20.

Example

Maximal 12 X 12 X 12 example
..............0
.............0.0
............0.0.1
...........0.0.1.0
..........1.1.1.1.0
.........0.1.0.0.0.0
........0.1.0.0.0.1.0
.......0.0.0.0.0.0.1.1
......0.1.0.0.0.0.0.1.0
.....1.1.1.0.0.0.0.1.0.0
....0.0.0.1.1.1.0.1.1.0.0
...0.0.0.0.1.0.0.0.0.1.0.0

Crossrefs

Sequence in context: A155410 A155429 A155346 * A155431 A155329 A155424

Adjacent sequences: A155395 A155396 A155397 * A155399 A155400 A155401

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved