A155325 Number of ways to place zero or more nonadjacent 1,1 2,1 3,0 3,1 3,2 4,1 5,1 polyhexes in any orientation on a planar n X n X n triangular grid.

1, 7, 19, 37, 133, 535, 2615, 17641, 119940, 924944, 8924108, 102805254, 1407633936, 22958195053, 437437783099

Offset

5,2

Links

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

Example

Maximal 10 X 10 X 10 example
............0
...........0.1
..........0.1.0
.........1.1.1.0
........0.1.0.0.0
.......0.1.0.0.1.0
......0.0.0.0.0.1.0
.....0.1.0.0.0.1.1.1
....1.1.1.1.1.0.0.1.0
...0.0.0.1.0.0.0.0.1.0

Crossrefs

Sequence in context: A155370 A155442 A155324 * A155255 A155251 A155239

Adjacent sequences: A155322 A155323 A155324 * A155326 A155327 A155328

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved