A155329 Number of ways to place zero or more nonadjacent 1,1 2,0 2,1 3,1 4,1 4,2 5,3 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 94, 403, 2775, 16917, 98970, 720295, 7051084, 87717398, 1205893340, 18539305616, 340372026066, 7675251517791

Offset

5,2

Links

Table of n, a(n) for n=5..20.

Example

Maximal 10 X 10 X 10 example
............0
...........0.0
..........0.1.0
.........1.1.1.1
........0.0.0.1.0
.......0.1.0.0.1.0
......1.1.0.0.0.0.1
.....0.1.0.0.0.0.1.0
....0.1.1.0.1.1.1.1.0
...0.0.0.1.0.0.1.0.0.0

Crossrefs

Sequence in context: A155346 A155398 A155431 * A155424 A155349 A155437

Adjacent sequences: A155326 A155327 A155328 * A155330 A155331 A155332

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved