A155425 Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 3,2 3,3 4,2 5,2 6,3 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 94, 289, 1342, 7169, 33736, 187935, 1191407, 9471948, 87427106, 862847938

Offset

6,2

Links

Table of n, a(n) for n=6..19.

Example

Maximal 12 X 12 X 12 example
..............0
.............0.0
............0.0.0
...........1.0.0.1
..........0.1.1.1.0
.........1.0.0.0.1.0
........0.1.0.0.0.1.1
.......0.1.0.0.0.0.0.0
......1.1.0.0.0.0.0.1.1
.....0.0.1.0.0.0.0.1.0.0
....0.0.0.1.0.1.1.1.0.0.0
...0.0.0.1.0.1.0.0.1.0.0.0

Crossrefs

Sequence in context: A155393 A155314 A155321 * A155410 A155429 A155346

Adjacent sequences: A155422 A155423 A155424 * A155426 A155427 A155428

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved