A155388 Number of ways to place zero or more nonadjacent 1,1 2,1 3,1 4,1 5,1 6,0 6,1 7,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 182, 832, 3129, 13751, 77260, 501790, 3395893, 27342352

Offset

7,2

Links

Table of n, a(n) for n=7..18.

Example

Maximal 11 X 11 X 11 example
.............0
............1.0
...........0.1.0
..........0.0.1.0
.........0.1.0.1.0
........0.1.0.0.1.0
.......0.1.0.0.0.1.1
......0.1.0.0.0.1.0.0
.....0.1.0.0.0.0.0.0.1
....1.1.0.1.1.1.1.1.1.0
...0.0.1.0.0.0.0.0.0.1.0

Crossrefs

Sequence in context: A155365 A155364 A155332 * A155367 A155357 A155248

Adjacent sequences: A155385 A155386 A155387 * A155389 A155390 A155391

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved