A155402 Number of ways to place zero or more nonadjacent 0,0 1,0 2,0 3,1 4,2 5,3 5,4 5,5 polyhexes in any orientation on a planar n X n X n triangular grid.

1, 4, 10, 22, 40, 161, 580, 2088, 9630, 52661, 324848, 2048063, 15783536, 139241607, 1379819761

Offset

5,2

Links

Table of n, a(n) for n=5..19.

Example

Maximal 10 X 10 X 10 example
............0
...........0.0
..........1.1.1
.........1.0.0.0
........1.0.1.1.1
.......1.0.0.0.0.1
......0.1.0.0.0.0.1
.....1.0.1.0.0.1.0.1
....0.1.0.0.0.1.0.1.0
...0.0.1.1.1.1.0.1.0.0

Crossrefs

Sequence in context: A155382 A155287 A155337 * A155232 A188281 A227327

Adjacent sequences: A155399 A155400 A155401 * A155403 A155404 A155405

Keyword

nonn

Author

R. H. Hardin, Jan 22 2009

Status

approved