A155218 Number of ways to place zero or more nonadjacent 1,0 1,1 2,0 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 64, 604, 5668, 60291, 1139786, 28911749, 917529031, 42684328880, 2779416860900, 242990212063594, 29572386974464964, 5010503933132486018, 1166195763716912084751, 374917567112932723176757

Offset

2,2

Links

Table of n, a(n) for n=2..18.

Example

Maximal 13 X 13 X 13 example
...............0
..............1.1
.............1.0.0
............0.0.1.1
...........1.1.0.0.1
..........1.0.0.1.0.0
.........0.0.1.1.0.1.1
........1.0.0.0.0.1.0.0
.......1.0.1.0.1.0.0.1.1
......0.1.0.1.0.1.1.0.0.1
.....1.0.0.1.0.0.0.0.1.0.0
....1.0.1.0.0.1.1.0.1.0.1.0
...0.1.0.1.1.0.0.1.0.1.0.1.1

Crossrefs

Sequence in context: A155401 A346851 A155384 * A305483 A046137 A193643

Adjacent sequences: A155215 A155216 A155217 * A155219 A155220 A155221

Keyword

nonn

Author

R. H. Hardin, Jan 22 2009

Status

approved