A155373 Number of ways to place zero or more nonadjacent 1,1 2,1 3,0 3,1 3,2 3,3 4,2 5,3 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 61, 206, 1719, 10844, 47433, 196187, 1471074, 18683007, 235351208, 2409858057, 25820260434, 404318889964, 8981163778542

Offset

5,2

Comments

Same series for 1,0 2,0 3,0 3,1 3,2 3,3 4,1 5,2 polyhexes.

Links

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

Example

Maximal 10 X 10 X 10 example
............0
...........0.1
..........0.1.0
.........1.1.1.1
........0.0.1.0.0
.......0.0.0.1.0.0
......0.0.1.0.0.0.1
.....1.1.1.0.1.1.1.0
....0.0.1.1.0.0.1.1.0
...0.0.1.0.1.0.1.0.1.0

Crossrefs

Sequence in context: A155448 A155446 A155372 * A155444 A155439 A155441

Adjacent sequences: A155370 A155371 A155372 * A155374 A155375 A155376

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved