A155343 Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 3,1 3,2 4,3 4,4 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 4, 10, 22, 55, 192, 702, 3882, 23422, 155527, 1170160, 10636314, 113496925, 1456900734, 21993819116

Offset

4,2

Links

Table of n, a(n) for n=4..18.

Example

Maximal 12 X 12 X 12 example
..............0
.............0.0
............0.1.0
...........1.1.1.1
..........1.0.0.0.1
.........0.0.1.1.0.0
........0.1.1.0.0.1.0
.......1.0.1.0.1.1.1.1
......1.0.1.0.1.0.0.0.1
.....0.1.0.1.0.0.0.1.0.0
....0.1.1.0.0.0.1.1.1.1.0
...0.0.0.1.1.0.1.0.0.0.1.0

Crossrefs

Sequence in context: A124697 A155426 A155421 * A155341 A189589 A025576

Adjacent sequences: A155340 A155341 A155342 * A155344 A155345 A155346

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved