A155301 Number of ways to place zero or more nonadjacent 1,0 1,1 2,0 3,1 3,2 4,1 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 13, 37, 73, 274, 2707, 30458, 210247, 1927098, 30544775, 732699440, 16750707651, 417262694530, 14440304500005, 706310189376904

Offset

4,2

Links

Table of n, a(n) for n=4..18.

Example

Maximal 13 X 13 X 13 example
...............0
..............0.1
.............1.1.0
............1.0.1.0
...........0.1.0.0.0
..........0.0.0.0.0.0
.........1.0.0.0.0.0.1
........1.0.1.0.0.1.0.1
.......0.1.1.0.0.0.1.1.0
......1.0.0.1.0.0.1.0.0.1
.....1.0.1.0.0.1.0.0.1.0.1
....0.1.1.0.1.1.0.1.0.1.1.0
...0.0.0.1.0.0.1.1.0.1.0.0.0

Crossrefs

Sequence in context: A083577 A155285 A155262 * A155284 A155304 A183454

Adjacent sequences: A155298 A155299 A155300 * A155302 A155303 A155304

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved