A155404 Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 2,2 3,0 3,1 4,0 4,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 4, 10, 22, 40, 135, 446, 2376, 12035, 65714, 364923, 2734456, 23495580, 245925457, 2738475904, 35447846068, 514467522739

Offset

4,2

Links

Table of n, a(n) for n=4..20.

Example

Maximal 9 X 9 X 9 example
...........1
..........1.0
.........0.1.1
........1.1.0.0
.......1.0.1.0.1
......0.0.0.0.0.1
.....1.0.1.0.1.1.0
....0.1.1.0.0.0.1.1
...1.1.0.1.1.0.1.0.1

Crossrefs

Sequence in context: A061777 A298030 A155369 * A155360 A155382 A155287

Adjacent sequences: A155401 A155402 A155403 * A155405 A155406 A155407

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved