A155303 Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 2,2 3,0 3,1 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 43, 94, 494, 5695, 45904, 323395, 2883082, 44465095, 991227125, 21279544840, 498763157584, 15169543858784, 654635049199556

Offset

3,2

Links

Table of n, a(n) for n=3..18.

Example

Maximal 12 X 12 X 12 example
..............1
.............0.1
............1.1.0
...........0.0.1.1
..........1.0.0.0.0
.........0.1.0.0.0.1
........1.1.0.0.1.1.0
.......1.0.1.0.1.0.1.1
......0.0.0.0.0.0.0.0.0
.....0.1.0.1.0.1.1.0.1.0
....1.1.0.0.1.1.0.0.0.1.1
...1.0.1.1.0.0.1.0.1.1.0.1

Crossrefs

Sequence in context: A139828 A247905 A048488 * A268801 A155275 A155268

Adjacent sequences: A155300 A155301 A155302 * A155304 A155305 A155306

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved