A155447 Number of ways to place zero or more nonadjacent 2,0 3,1 3,2 4,2 4,3 4,4 5,2 6,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 61, 248, 1219, 8302, 40919, 212586, 1454728, 13983083, 157730943, 1851906541, 23225168793, 351573878630, 6540083828707

Offset

6,2

Links

Table of n, a(n) for n=6..22.

Example

Maximal 11 X 11 X 11 example
.............0
............0.0
...........0.0.1
..........0.1.1.0
.........1.1.1.0.0
........0.0.0.1.0.0
.......0.0.1.0.1.0.1
......0.1.1.0.0.0.1.0
.....1.1.1.0.1.1.1.0.0
....0.0.0.1.0.0.1.1.0.0
...0.0.0.0.1.0.0.0.1.0.0

Crossrefs

Sequence in context: A155444 A155439 A155441 * A155340 A155409 A155406

Adjacent sequences: A155444 A155445 A155446 * A155448 A155449 A155450

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved