A155424 Number of ways to place zero or more nonadjacent 1,1 2,0 2,1 3,2 4,3 4,4 5,3 5,4 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 97, 385, 1752, 10474, 62128, 377334, 2749676, 25769709, 285285035, 3566431622, 50164255930, 808544899113

Offset

5,2

Links

Table of n, a(n) for n=5..20.

Example

Maximal 10 X 10 X 10 example
............0
...........1.1
..........1.1.0
.........0.0.1.0
........0.0.0.1.1
.......1.0.0.1.0.0
......0.1.1.0.0.0.0
.....0.1.0.0.1.0.0.1
....1.1.0.0.1.1.1.1.0
...0.1.1.0.0.1.0.0.1.0

Crossrefs

Sequence in context: A155398 A155431 A155329 * A155349 A155437 A155299

Adjacent sequences: A155421 A155422 A155423 * A155425 A155426 A155427

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved