A155439 Number of ways to place zero or more nonadjacent 2,1 2,2 3,0 3,1 4,2 4,3 5,1 5,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 61, 224, 1849, 11422, 49927, 232499, 1829873, 22757837, 281467930, 3021365293, 36143191129, 595788136987, 13215044372764

Offset

5,2

Links

Table of n, a(n) for n=5..21.

Example

Maximal 10 X 10 X 10 example
............0
...........1.0
..........1.0.1
.........0.1.1.0
........0.1.0.1.0
.......0.0.0.1.0.0
......0.1.1.0.0.1.0
.....1.1.0.0.1.0.1.1
....0.0.1.1.0.1.1.0.1
...0.1.1.0.0.0.0.1.0.0

Crossrefs

Sequence in context: A155372 A155373 A155444 * A155441 A155447 A155340

Adjacent sequences: A155436 A155437 A155438 * A155440 A155441 A155442

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved