A155444 Number of ways to place zero or more nonadjacent 2,0 3,0 4,1 4,2 4,3 4,4 5,1 6,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 61, 215, 976, 6510, 31895, 148311, 835105, 6965183, 70259384, 771053702, 8287139754, 101882179551

Offset

6,2

Links

Table of n, a(n) for n=6..21.

Example

Maximal 11 X 11 X 11 example
.............0
............0.0
...........1.0.0
..........1.0.0.0
.........0.1.1.1.1
........0.1.0.0.0.0
.......1.0.1.0.1.0.0
......0.1.0.0.0.1.0.0
.....0.0.1.0.1.0.1.0.1
....0.0.0.1.1.0.0.1.1.0
...0.0.1.1.0.0.1.1.0.0.0

Crossrefs

Sequence in context: A155446 A155372 A155373 * A155439 A155441 A155447

Adjacent sequences: A155441 A155442 A155443 * A155445 A155446 A155447

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved