A155284 Number of ways to place zero or more nonadjacent 1,0 1,1 2,1 3,1 4,2 4,3 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 13, 37, 73, 309, 2413, 28031, 212649, 2010251, 29604759, 633868196, 15160513746, 396011442436, 13223926465865, 597617100526032

Offset

4,2

Links

Table of n, a(n) for n=4..18.

Example

Maximal 11 X 11 X 11 example
.............0
............1.0
...........1.1.1
..........0.0.0.1
.........0.1.0.1.0
........1.1.1.0.0.0
.......1.0.0.0.0.1.1
......0.1.0.1.1.0.0.1
.....1.0.0.0.0.1.0.1.0
....1.1.0.1.0.1.0.1.1.0
...0.0.1.1.0.1.1.0.0.0.0

Crossrefs

Sequence in context: A155285 A155262 A155301 * A155304 A183454 A155265

Adjacent sequences: A155281 A155282 A155283 * A155285 A155286 A155287

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved