A155441 Number of ways to place zero or more nonadjacent 2,1 3,0 3,1 3,3 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, 49981, 224398, 1780640, 22690257, 281350590, 2951548767, 34313995173, 571260880157, 12982237127311

Offset

5,2

Links

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

Example

Maximal 10 X 10 X 10 example
............0
...........0.1
..........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
....1.0.1.1.0.1.1.0.0
...0.0.1.0.0.0.0.1.1.0

Crossrefs

Sequence in context: A155373 A155444 A155439 * A155447 A155340 A155409

Adjacent sequences: A155438 A155439 A155440 * A155442 A155443 A155444

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved