A155267 Number of ways to place zero or more nonadjacent 0,0 1,0 1,1 2,1 3,1 4,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 13, 37, 79, 475, 4903, 39377, 335194, 4601560, 86035793, 1817145359, 47456653666, 1611117096227, 70329597516837

Offset

4,2

Links

Table of n, a(n) for n=4..17.

Example

Maximal 13 X 13 X 13 example
...............1
..............1.1
.............0.1.0
............0.1.0.0
...........1.0.1.0.0
..........1.1.0.0.1.1
.........0.1.0.0.1.1.0
........0.1.0.1.1.0.0.0
.......0.0.1.0.0.0.1.0.1
......0.0.0.0.0.0.1.1.0.1
.....0.1.1.0.1.1.0.1.0.1.0
....1.1.0.0.1.1.0.1.0.1.1.0
...1.1.0.1.1.0.0.0.1.0.1.0.0

Crossrefs

Sequence in context: A163675 A152610 A155264 * A157837 A039367 A139697

Adjacent sequences: A155264 A155265 A155266 * A155268 A155269 A155270

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved