A155260 Number of ways to place zero or more nonadjacent 1,0 1,1 2,1 2,2 3,1 4,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 25, 55, 130, 1405, 16466, 116148, 894657, 15191483, 400416491, 9046002744, 215811308360, 8089887873673, 451390921829837

Offset

3,2

Comments

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

Links

Table of n, a(n) for n=3..17.

Example

Maximal 11 X 11 X 11 example
.............0
............1.1
...........0.1.1
..........1.1.0.0
.........0.0.0.1.1
........1.0.1.0.1.1
.......1.1.1.0.1.0.0
......0.1.0.0.0.1.0.1
.....1.0.0.1.1.0.0.1.0
....1.1.1.0.0.1.1.0.1.1
...0.1.0.1.0.1.1.0.1.1.0

Crossrefs

Sequence in context: A071778 A350156 A155250 * A155244 A155310 A155288

Adjacent sequences: A155257 A155258 A155259 * A155261 A155262 A155263

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved