A155268 Number of ways to place zero or more nonadjacent 1,1 2,1 3,0 3,1 3,2 3,3 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 43, 106, 668, 7101, 59172, 470802, 4838017, 83647134, 1916327385, 46633700220, 1291488803553, 46130099469946

Offset

3,2

Comments

Same series for 1,1 2,1 2,2 3,0 3,1 3,3 polyhexes.

Same series for 0,0 1,0 1,1 2,0 2,2 3,0 polyhexes.

Links

Table of n, a(n) for n=3..17.

Example

Maximal 12 X 12 X 12 example
..............1
.............0.1
............1.1.1
...........0.0.0.1
..........0.0.0.0.0
.........1.0.0.0.0.1
........0.1.0.0.0.0.1
.......1.1.1.1.0.1.1.1
......0.0.0.0.0.0.0.0.1
.....1.0.1.1.1.1.0.1.0.0
....0.1.0.0.1.0.0.0.1.0.0
...1.1.1.1.0.1.0.1.1.1.1.0

Crossrefs

Sequence in context: A155303 A268801 A155275 * A124700 A155336 A155427

Adjacent sequences: A155265 A155266 A155267 * A155269 A155270 A155271

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved