A155406 Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 2,2 3,0 3,1 4,2 5,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 61, 275, 1793, 9603, 41441, 206821, 1678073, 16665525, 168175105, 1702776291, 20351416873, 312390331791

Offset

5,2

Links

Table of n, a(n) for n=5..20.

Example

Maximal 10 X 10 X 10 example
............0
...........0.0
..........1.0.1
.........0.1.1.0
........1.1.0.0.0
.......1.0.1.0.0.0
......0.0.0.0.1.0.1
.....1.0.1.1.0.1.1.0
....0.1.1.0.0.0.0.1.1
...1.1.0.1.0.0.0.1.0.1

Crossrefs

Sequence in context: A155447 A155340 A155409 * A155352 A155361 A155315

Adjacent sequences: A155403 A155404 A155405 * A155407 A155408 A155409

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved