A155409 Number of ways to place zero or more nonadjacent 1,1 2,0 2,1 3,2 3,3 4,2 4,4 5,3 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 61, 275, 1767, 10441, 45245, 228435, 1707103, 18329337, 206589973, 2188693403, 25302969335, 385488957361, 7496386108989

Offset

5,2

Links

Table of n, a(n) for n=5..21.

Example

Maximal 10 X 10 X 10 example
............0
...........0.1
..........1.0.1
.........0.1.1.0
........0.0.0.1.1
.......1.0.0.1.0.0
......1.0.1.0.0.0.0
.....0.1.1.0.1.1.0.1
....1.1.0.0.0.0.1.1.0
...0.0.1.0.0.1.1.0.1.0

Crossrefs

Sequence in context: A155441 A155447 A155340 * A155406 A155352 A155361

Adjacent sequences: A155406 A155407 A155408 * A155410 A155411 A155412

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved