A155281 Number of ways to place zero or more nonadjacent 0,0 1,0 2,0 3,0 4,1 4,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 25, 76, 289, 1579, 11207, 100558, 1021474, 12631241, 194406300, 3780423351, 90519767008

Offset

4,2

Links

Table of n, a(n) for n=4..16.

Example

Maximal 13 X 13 X 13 example
...............1
..............0.1
.............0.0.1
............1.0.0.1
...........1.0.1.1.0
..........1.0.0.0.0.0
.........1.0.0.0.1.0.0
........0.1.1.0.1.0.1.1
.......1.0.0.0.1.0.1.0.1
......1.0.0.0.1.0.0.0.0.1
.....1.0.0.1.0.1.1.0.1.0.1
....1.0.0.1.0.0.0.0.1.0.0.0
...0.1.1.0.1.1.1.1.0.1.1.1.1

Crossrefs

Sequence in context: A048477 A294837 A117152 * A155254 A155295 A168589

Adjacent sequences: A155278 A155279 A155280 * A155282 A155283 A155284

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved