A155331 Number of ways to place zero or more nonadjacent 1,0 1,1 2,0 3,0 4,0 5,0 6,1 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 4, 13, 28, 131, 616, 2577, 12364, 77884, 560672, 4490012, 45293635, 525483762

Offset

5,2

Links

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

Example

Maximal 9 X 9 X 9 example
...........0
..........1.1
.........1.0.0
........1.0.1.1
.......1.0.0.0.1
......1.0.0.0.0.1
.....0.1.0.0.0.0.1
....1.0.0.0.0.1.0.1
...0.1.1.1.1.1.0.1.0

Crossrefs

Sequence in context: A155238 A155320 A155279 * A155387 A155366 A340002

Adjacent sequences: A155328 A155329 A155330 * A155332 A155333 A155334

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved