A155438 Number of ways to place zero or more nonadjacent 2,1 2,2 3,1 4,0 4,1 5,2 6,3 6,4 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 73, 192, 799, 5700, 31065, 143784, 760292, 5454945, 52282160, 593679020, 6642535818, 77363263396

Offset

6,2

Links

Table of n, a(n) for n=6..21.

Example

Maximal 11 X 11 X 11 example
.............0
............0.0
...........1.0.0
..........0.1.1.1
.........0.1.0.0.1
........0.1.0.0.0.0
.......1.0.1.0.1.1.0
......1.0.0.0.0.0.1.0
.....0.1.0.0.1.0.0.1.1
....0.0.1.1.1.0.0.1.0.0
...0.0.1.0.0.0.1.1.0.0.0

Crossrefs

Sequence in context: A155420 A155434 A155378 * A155396 A155411 A155436

Adjacent sequences: A155435 A155436 A155437 * A155439 A155440 A155441

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved