A155327 Number of ways to place zero or more nonadjacent 1,1 2,1 3,0 3,1 3,2 4,2 5,3 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 76, 382, 2724, 16177, 82034, 576215, 5993574, 76883371, 996696560, 14175824222, 255455613029

Offset

5,2

Links

Table of n, a(n) for n=5..19.

Example

Maximal 10 X 10 X 10 example
............0
...........0.0
..........0.0.1
.........1.1.1.0
........0.0.1.1.0
.......0.1.0.0.1.0
......0.1.0.0.0.0.1
.....1.1.1.0.0.1.1.0
....0.0.1.0.1.1.1.0.0
...0.0.0.1.0.0.0.1.0.0

Crossrefs

Sequence in context: A155411 A155436 A155440 * A155363 A155395 A155342

Adjacent sequences: A155324 A155325 A155326 * A155328 A155329 A155330

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved