A155291 Number of ways to place zero or more nonadjacent 1,0 1,1 2,0 3,0 4,1 5,1 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 25, 70, 430, 2529, 13389, 123723, 1442773, 16315566, 272990681, 5489382645

Offset

4,2

Links

Table of n, a(n) for n=4..15.

Example

Maximal 11 X 11 X 11 example
.............0
............1.1
...........0.0.1
..........0.1.0.1
.........1.1.0.1.0
........1.0.0.0.1.0
.......1.0.0.1.0.0.1
......0.1.0.1.0.0.0.1
.....0.0.0.0.1.0.0.1.0
....1.1.1.0.0.1.1.0.1.0
...1.0.0.1.1.0.0.1.0.1.1

Crossrefs

Sequence in context: A247620 A240156 A155245 * A155221 A213569 A299269

Adjacent sequences: A155288 A155289 A155290 * A155292 A155293 A155294

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved