A155369 Number of ways to place zero or more nonadjacent 0,0 1,0 1,1 2,1 3,1 3,2 4,1 4,3 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 4, 10, 22, 40, 103, 496, 3099, 16980, 88897, 547244, 4508233, 48937458, 595010305, 7745612856, 114311761273

Offset

4,2

Links

Table of n, a(n) for n=4..19.

Example

Maximal 11 X 11 X 11 example
.............0
............0.1
...........0.1.0
..........1.1.1.1
.........1.1.0.0.0
........0.0.0.0.1.1
.......0.0.1.1.1.1.0
......1.0.0.0.1.0.0.1
.....0.1.0.0.1.0.0.1.0
....1.1.1.1.0.0.1.1.1.1
...0.0.0.1.1.0.1.1.0.0.0

Crossrefs

Sequence in context: A177736 A061777 A298030 * A155404 A155360 A155382

Adjacent sequences: A155366 A155367 A155368 * A155370 A155371 A155372

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved