A155412 Number of ways to place zero or more nonadjacent 1,0 1,1 2,0 3,1 3,2 4,3 5,2 5,3 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 67, 231, 1339, 8869, 45413, 237925, 1625066, 15388021, 179623547, 2180692829, 28227148274, 428766984919

Offset

5,2

Links

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

Example

Maximal 10 X 10 X 10 example
............0
...........0.0
..........1.1.0
.........1.0.1.0
........0.0.1.0.1
.......1.1.0.1.1.0
......0.0.1.0.0.0.1
.....0.1.1.0.1.1.0.1
....0.1.0.0.1.0.1.1.0
...0.0.1.1.0.1.0.0.0.0

Crossrefs

Sequence in context: A213489 A288021 A155394 * A155420 A155434 A155378

Adjacent sequences: A155409 A155410 A155411 * A155413 A155414 A155415

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved