A155382 Number of ways to place zero or more nonadjacent 0,0 1,0 2,0 2,1 3,2 4,2 4,3 4,4 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 4, 10, 22, 40, 141, 496, 2636, 13567, 76878, 469481, 3693548, 33420872, 360497441, 4317343069, 60086409152

Offset

4,2

Links

Table of n, a(n) for n=4..19.

Example

Maximal 9 X 9 X 9 example
...........1
..........0.1
.........0.1.1
........0.1.0.0
.......1.1.1.0.1
......0.0.0.0.1.0
.....1.0.1.0.1.1.0
....1.1.1.1.0.0.1.0
...1.0.0.0.1.0.1.1.1

Crossrefs

Sequence in context: A155369 A155404 A155360 * A155287 A155337 A155402

Adjacent sequences: A155379 A155380 A155381 * A155383 A155384 A155385

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved