A155307 Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 3,0 3,1 4,0 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 4, 13, 37, 146, 620, 2737, 17298, 136979, 1185666, 12752003, 161758550, 2364549128, 42702118766

Offset

4,2

Comments

Same series for 0,0 1,0 2,0 2,1 3,0 3,1 4,0 polyhexes.

Links

Table of n, a(n) for n=4..17.

Example

Maximal 11 X 11 X 11 example
.............1
............0.1
...........0.1.0
..........1.0.1.1
.........1.0.0.0.1
........0.1.0.0.0.0
.......1.1.0.0.1.1.0
......1.0.0.1.1.0.1.1
.....0.0.0.0.0.0.0.0.0
....1.1.0.1.1.0.0.1.1.0
...0.0.1.1.0.0.1.1.0.1.1

Crossrefs

Sequence in context: A297391 A108489 A155375 * A155344 A155418 A155235

Adjacent sequences: A155304 A155305 A155306 * A155308 A155309 A155310

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved