A155394 Number of ways to place zero or more nonadjacent 1,1 2,1 3,0 3,1 4,2 4,3 5,2 6,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 67, 219, 1086, 6381, 31966, 154641, 952314, 7600004, 73667522, 781898311, 8779500403

Offset

6,2

Links

Table of n, a(n) for n=6..20.

Example

Maximal 11 X 11 X 11 example
.............0
............1.0
...........0.1.0
..........0.0.1.1
.........0.1.1.0.0
........0.0.0.1.0.0
.......0.0.1.0.1.0.0
......1.0.1.0.0.0.1.0
.....0.1.1.0.1.1.1.0.0
....0.1.0.1.0.0.0.1.1.1
...0.1.0.0.0.0.0.1.0.0.0

Crossrefs

Sequence in context: A121091 A213489 A288021 * A155412 A155420 A155434

Adjacent sequences: A155391 A155392 A155393 * A155395 A155396 A155397

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved