A155448 Number of ways to place zero or more nonadjacent 2,0 3,1 4,2 4,3 4,4 5,2 6,2 7,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 61, 198, 925, 4932, 25307, 120759, 705438, 5070257, 44891211, 447175598, 4812407060, 57607358493

Offset

7,2

Links

Table of n, a(n) for n=7..22.

Example

Maximal 12 X 12 X 12 example
..............0
.............0.0
............0.0.1
...........0.0.1.0
..........1.1.1.0.0
.........0.0.0.1.0.0
........0.0.1.0.1.0.0
.......0.0.1.0.0.1.0.1
......0.0.1.0.0.0.0.1.0
.....1.1.1.0.1.1.1.1.0.0
....0.0.0.1.0.0.0.0.1.0.0
...0.0.0.0.1.0.0.0.0.1.0.0

Crossrefs

Sequence in context: A098484 A155443 A155405 * A155446 A155372 A155373

Adjacent sequences: A155445 A155446 A155447 * A155449 A155450 A155451

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved