A155362 Number of ways to place zero or more nonadjacent 0,0 1,0 1,1 2,0 2,2 3,1 3,2 4,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 4, 10, 19, 31, 142, 704, 3110, 11340, 67080, 521405, 4456035, 36267075, 359062706, 4494388097, 66854020627, 1071365619565, 19550448735686

Offset

4,2

Links

Table of n, a(n) for n=4..21.

Example

Maximal 9 X 9 X 9 example
...........1
..........1.1
.........1.0.1
........0.1.1.0
.......0.0.1.0.0
......0.0.0.0.0.0
.....1.1.1.0.1.1.1
....1.0.1.0.0.1.0.1
...1.1.1.0.0.0.1.1.1

Crossrefs

Sequence in context: A063773 A155432 A155302 * A034966 A301256 A301092

Adjacent sequences: A155359 A155360 A155361 * A155363 A155364 A155365

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved