A155392 Number of ways to place zero or more nonadjacent 1,1 2,1 3,0 3,1 4,2 4,3 4,4 5,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 4, 13, 28, 49, 96, 501, 3463, 18127, 74376, 331418, 2409920, 26775212, 305337017, 3047283148, 31207251008, 409221933719

Offset

5,2

Links

Table of n, a(n) for n=5..21.

Example

Maximal 10 X 10 X 10 example
............0
...........1.0
..........0.1.0
.........0.0.1.1
........1.1.1.0.0
.......0.0.0.1.0.1
......1.0.1.0.0.1.0
.....0.1.1.0.1.1.0.0
....0.1.0.1.0.0.1.1.1
...0.1.0.0.1.0.1.0.0.0

Crossrefs

Sequence in context: A273557 A272790 A273564 * A155435 A155371 A155355

Adjacent sequences: A155389 A155390 A155391 * A155393 A155394 A155395

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved