A155253 Number of ways to place zero or more nonadjacent 1,1 2,0 2,1 2,2 3,1 4,1 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 13, 37, 73, 378, 3421, 36342, 293256, 3406317, 59935388, 1419179921, 37034743264, 1162832741191, 48524067272860

Offset

4,2

Links

Table of n, a(n) for n=4..17.

Example

Maximal 11 X 11 X 11 example
.............0
............1.0
...........1.1.1
..........0.0.1.0
.........1.0.0.1.0
........1.1.1.0.0.0
.......0.0.1.0.0.0.0
......0.1.0.1.0.0.1.0
.....1.1.0.0.0.1.0.1.1
....0.1.0.1.1.1.1.0.1.0
...0.1.1.0.0.1.0.0.1.1.0

Crossrefs

Sequence in context: A155304 A183454 A155265 * A155234 A222964 A296312

Adjacent sequences: A155250 A155251 A155252 * A155254 A155255 A155256

Keyword

nonn

Author

R. H. Hardin, Jan 22 2009

Status

approved