A155383 Number of ways to place zero or more nonadjacent 1,1 2,1 3,0 3,1 4,1 4,2 5,1 6,1 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 4, 10, 19, 52, 161, 487, 1787, 8270, 41329, 223486, 1401458, 9925976, 78514707, 707922309, 7286793032

Offset

6,2

Links

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

Example

Maximal 11 X 11 X 11 example
.............0
............1.0
...........0.1.0
..........0.0.1.1
.........0.0.1.1.0
........0.1.0.0.1.0
.......0.1.0.0.0.1.0
......1.1.0.0.0.0.0.0
.....0.1.1.0.0.0.1.0.0
....0.1.0.0.1.1.1.1.1.1
...0.1.0.0.0.0.0.1.0.0.0

Crossrefs

Sequence in context: A155322 A251176 A155428 * A155229 A155220 A300018

Adjacent sequences: A155380 A155381 A155382 * A155384 A155385 A155386

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved