A155240 Number of ways to place zero or more nonadjacent 0,0 1,0 2,0 3,1 3,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 25, 55, 208, 1905, 20926, 172576, 1900996, 35023141, 893053190, 24012955958, 788590457332, 36088248750672

Offset

3,2

Comments

Same series for 1,1 2,1 2,2 3,0 3,1 3,2 polyhexes.

Links

Table of n, a(n) for n=3..16.

Example

Maximal 11 X 11 X 11 example
.............0
............1.1
...........1.0.1
..........0.0.0.1
.........1.0.0.0.0
........1.0.0.0.1.1
.......0.1.1.1.0.0.1
......0.0.0.0.0.0.1.0
.....1.1.1.0.1.0.1.0.1
....1.0.0.0.0.1.0.0.0.1
...0.1.0.1.1.1.0.1.1.1.0

Crossrefs

Sequence in context: A155311 A155289 A155306 * A155298 A155292 A155276

Adjacent sequences: A155237 A155238 A155239 * A155241 A155242 A155243

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved