A155336 Number of ways to place zero or more nonadjacent 1,0 1,1 2,0 3,0 4,1 5,2 5,3 polyhexes in any orientation on a planar n X n X n triangular grid.

1, 7, 19, 43, 112, 333, 1722, 11278, 66471, 421203, 3100169, 28603780, 333898461, 4399044128, 64174608851

Offset

5,2

Links

Table of n, a(n) for n=5..19.

Example

Maximal 11 X 11 X 11 example
.............0
............0.0
...........1.1.1
..........1.0.0.1
.........0.0.0.0.1
........0.0.0.0.1.0
.......1.1.0.0.0.0.0
......1.0.0.1.0.1.1.1
.....1.0.0.1.0.1.0.0.1
....0.1.0.0.1.0.0.1.0.1
...0.0.1.1.0.1.1.1.0.1.0

Crossrefs

Sequence in context: A155275 A155268 A124700 * A155427 A155403 A155350

Adjacent sequences: A155333 A155334 A155335 * A155337 A155338 A155339

Keyword

nonn

Author

R. H. Hardin, Jan 22 2009

Status

approved