A155379 Number of ways to place zero or more nonadjacent 0,0 1,0 2,0 2,1 3,1 3,2 4,2 5,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 100, 521, 3034, 15439, 84733, 680192, 6722018, 71127189, 839682580, 12147844032

Offset

5,2

Links

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

Example

Maximal 10 X 10 X 10 example
............0
...........0.0
..........1.0.0
.........0.1.1.1
........1.0.1.1.1
.......1.0.0.0.0.1
......1.1.0.0.0.0.0
.....0.1.1.0.1.1.1.0
....0.0.1.0.0.0.1.1.0
...0.0.1.0.0.0.0.1.1.1

Crossrefs

Sequence in context: A155349 A155437 A155299 * A155243 A155417 A155416

Adjacent sequences: A155376 A155377 A155378 * A155380 A155381 A155382

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved