A155321 Number of ways to place zero or more nonadjacent 0,0 1,0 1,1 2,0 3,1 3,2 4,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 88, 676, 4377, 23168, 128083, 1375195, 16989531, 217989023, 2931139962, 55566047699, 1303222849730, 35399619266821

Offset

4,2

Comments

Same series for 0,0 1,0 2,1 2,2 3,1 4,2 polyhexes.

Same series for 0,0 1,0 1,1 2,0 2,1 3,1 3,2 4,2 polyhexes.

Links

Table of n, a(n) for n=4..19.

Example

Maximal 9 X 9 X 9 example
...........0
..........0.0
.........1.1.1
........0.1.0.1
.......0.0.0.1.1
......0.0.0.0.0.0
.....1.1.0.0.1.1.1
....0.1.0.1.0.1.0.1
...0.0.1.1.1.0.0.1.1

Crossrefs

Sequence in context: A155381 A155393 A155314 * A155425 A155410 A155429

Adjacent sequences: A155318 A155319 A155320 * A155322 A155323 A155324

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved