A155385 Number of ways to place zero or more nonadjacent 0,0 1,0 2,0 3,0 3,1 4,1 5,2 6,3 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 52, 181, 571, 2900, 15410, 91393, 670564, 5234213, 49806306, 539502855

Offset

6,2

Links

Table of n, a(n) for n=6..18.

Example

Maximal 12 X 12 X 12 example
..............1
.............0.1
............1.0.1
...........1.0.1.1
..........1.0.0.1.0
.........1.1.0.1.0.1
........0.1.0.1.0.0.1
.......0.0.1.0.0.0.0.1
......1.0.0.1.0.0.0.1.1
.....0.1.0.0.0.0.0.0.1.0
....0.0.1.1.0.0.0.0.1.0.0
...0.0.0.1.1.1.1.0.1.0.0.0

Crossrefs

Sequence in context: A100450 A155423 A155347 * A155345 A155309 A155419

Adjacent sequences: A155382 A155383 A155384 * A155386 A155387 A155388

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved