A155446 Number of ways to place zero or more nonadjacent 2,0 3,1 3,2 4,1 4,3 4,4 5,2 6,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 61, 198, 961, 7036, 35739, 164475, 1020808, 9067997, 101564763, 1167745653, 13478588062, 184107863480, 3150709806656, 65431262534013

Offset

6,2

Links

Table of n, a(n) for n=6..23.

Example

Maximal 11 X 11 X 11 example
.............0
............0.0
...........1.0.0
..........0.1.1.0
.........0.1.0.1.1
........0.0.1.0.0.0
.......1.0.1.0.1.0.0
......0.1.0.0.0.1.1.0
.....0.1.0.1.1.0.0.1.1
....0.0.1.1.0.0.1.1.0.0
...0.0.1.0.0.0.1.0.0.0.0

Crossrefs

Sequence in context: A155443 A155405 A155448 * A155372 A155373 A155444

Adjacent sequences: A155443 A155444 A155445 * A155447 A155448 A155449

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved