A155421 Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 3,1 4,2 4,3 5,4 5,5 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 4, 10, 22, 55, 192, 618, 2255, 11708, 67218, 421461, 2956054, 24412206, 225564175

Offset

5,2

Links

Table of n, a(n) for n=5..18.

Example

Maximal 10 X 10 X 10 example
............1
...........1.0
..........0.1.0
.........0.1.0.0
........1.0.1.1.0
.......0.1.0.0.1.1
......0.1.0.0.0.0.0
.....0.0.1.0.0.1.1.0
....0.1.1.0.1.1.0.1.1
...1.1.0.0.1.0.0.0.0.1

Crossrefs

Sequence in context: A318416 A124697 A155426 * A155343 A155341 A189589

Adjacent sequences: A155418 A155419 A155420 * A155422 A155423 A155424

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved