A155309 Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 3,1 4,2 5,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 52, 196, 938, 5406, 33082, 270615, 2652565, 30092725, 403696211, 6603268906

Offset

5,2

Links

Table of n, a(n) for n=5..17.

Example

Maximal 13 X 13 X 13 example
...............0
..............0.0
.............0.0.1
............0.1.1.0
...........1.1.0.0.1
..........1.0.0.0.1.0
.........0.0.1.1.0.1.0
........0.1.1.0.0.1.0.1
.......1.1.0.0.0.0.1.0.1
......0.0.0.1.0.0.1.0.1.0
.....1.1.0.0.1.1.0.0.0.1.0
....0.0.1.1.0.0.1.1.0.1.0.0
...0.0.0.0.1.1.0.0.1.0.1.0.0

Crossrefs

Sequence in context: A155347 A155385 A155345 * A155419 A155246 A155414

Adjacent sequences: A155306 A155307 A155308 * A155310 A155311 A155312

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved