A155403 Number of ways to place zero or more nonadjacent 0,0 1,0 2,0 3,1 4,2 5,3 6,3 7,3 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 43, 130, 472, 2062, 9990, 51107, 296798, 2149983, 17713635

Offset

7,2

Links

Table of n, a(n) for n=7..18.

Example

Maximal 10 X 10 X 10 example
............0
...........0.0
..........0.0.0
.........1.0.0.0
........0.1.0.0.0
.......1.0.1.1.1.1
......0.1.0.0.0.0.1
.....0.0.1.1.1.1.0.1
....0.0.0.0.0.0.1.0.0
...0.0.0.0.0.0.0.1.0.0

Crossrefs

Sequence in context: A124700 A155336 A155427 * A155350 A155312 A155351

Adjacent sequences: A155400 A155401 A155402 * A155404 A155405 A155406

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved