A155259 Number of ways to place zero or more nonadjacent 0,0 1,0 1,1 2,0 3,0 4,1 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 13, 37, 111, 999, 5261, 42873, 550367, 5937880, 97204725, 2096426420, 47838274736

Offset

4,2

Links

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

Example

Maximal 10 X 10 X 10 example
............0
...........1.1
..........0.0.1
.........1.0.0.1
........1.1.0.1.1
.......1.0.0.0.0.0
......1.0.1.1.0.1.1
.....0.1.0.0.1.0.1.0
....1.0.0.1.0.1.0.1.0
...1.1.1.1.0.1.1.0.1.1

Crossrefs

Sequence in context: A155228 A126367 A139926 * A155308 A166101 A333281

Adjacent sequences: A155256 A155257 A155258 * A155260 A155261 A155262

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved