A155314 Number of ways to place zero or more nonadjacent 2,1 2,2 3,0 3,1 4,2 4,3 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 88, 640, 5031, 26752, 151436, 1596386, 24274062, 343210818, 4865294909, 96524596845, 2686621268327, 85799102830215

Offset

4,2

Comments

Same series for 1,1 2,0 2,1 2,2 3,1 3,2 4,3 polyhexes.

Links

Table of n, a(n) for n=4..19.

Example

Maximal 13 X 13 X 13 example
...............0
..............1.0
.............1.0.1
............0.1.1.0
...........0.1.0.0.0
..........0.0.0.0.0.1
.........0.0.0.0.1.0.1
........0.1.1.0.0.1.1.0
.......0.0.0.1.1.0.0.1.0
......0.0.1.1.0.0.1.0.0.1
.....1.1.0.0.0.1.1.0.1.0.1
....0.0.1.1.0.1.0.1.0.1.1.0
...0.1.1.0.0.0.0.1.0.0.0.1.0

Crossrefs

Sequence in context: A237052 A155381 A155393 * A155321 A155425 A155410

Adjacent sequences: A155311 A155312 A155313 * A155315 A155316 A155317

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved