A155393 Number of ways to place zero or more nonadjacent 1,0 1,1 2,1 3,1 4,2 4,3 4,4 5,4 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 88, 374, 1596, 9550, 53268, 321912, 2348995, 21763014, 230932203, 2808007076, 38499914560, 608992059466

Offset

5,2

Links

Table of n, a(n) for n=5..20.

Example

Maximal 10 X 10 X 10 example
............0
...........1.1
..........0.1.0
.........0.0.1.0
........1.1.1.0.0
.......0.1.0.0.1.1
......0.0.0.0.0.1.0
.....0.1.1.0.0.1.0.0
....1.1.0.1.1.0.1.1.1
...0.1.0.0.1.0.0.0.1.0

Crossrefs

Sequence in context: A155317 A237052 A155381 * A155314 A155321 A155425

Adjacent sequences: A155390 A155391 A155392 * A155394 A155395 A155396

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved