A155415 Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 3,0 3,1 4,2 5,2 6,3 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 46, 127, 385, 1900, 9866, 51376, 316958, 2204777, 18653197, 179171339, 1914846570

Offset

6,2

Links

Table of n, a(n) for n=6..19.

Example

Maximal 11 X 11 X 11 example
.............0
............1.0
...........1.0.1
..........0.1.0.1
.........1.1.0.1.0
........0.0.1.0.1.1
.......0.0.1.0.1.0.0
......1.0.0.1.0.1.0.0
.....0.1.1.0.0.1.0.0.0
....0.0.0.1.1.0.0.0.0.0
...0.0.0.1.0.1.1.0.0.0.0

Crossrefs

Sequence in context: A268926 A212955 A372881 * A155273 A277613 A278403

Adjacent sequences: A155412 A155413 A155414 * A155416 A155417 A155418

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved