A155288 Number of ways to place zero or more nonadjacent 0,0 1,0 2,0 3,1 3,2 4,1 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 25, 55, 187, 1099, 9278, 75511, 645474, 7422000, 116915443, 2299714950, 51760679784, 1407030104754

Offset

4,2

Links

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

Example

Maximal 10 X 10 X 10 example
............0
...........1.0
..........0.1.1
.........0.1.0.1
........0.0.0.0.1
.......1.1.1.0.0.0
......0.0.0.1.1.0.0
.....0.1.0.1.0.0.1.0
....1.1.0.0.0.1.1.0.0
...0.0.1.1.1.0.0.1.1.1

Crossrefs

Sequence in context: A155260 A155244 A155310 * A155293 A155311 A155289

Adjacent sequences: A155285 A155286 A155287 * A155289 A155290 A155291

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved