A155361 Number of ways to place zero or more nonadjacent 1,1 2,0 2,1 2,2 3,1 3,3 4,2 4,3 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 61, 398, 3352, 18677, 76887, 524948, 7212413, 105020342, 1220235443, 15236713872, 301443806483, 8288724969974, 237668565804989, 6783028496183063

Offset

4,2

Comments

Same series for 1,1 2,0 2,1 3,2 3,3 4,2 4,3 polyhexes.

Same series for 1,0 1,1 2,0 2,2 3,0 3,2 4,2 polyhexes.

Same series for 1,0 1,1 2,0 2,1 2,2 3,0 3,2 4,2 polyhexes.

Links

Table of n, a(n) for n=4..21.

Example

Maximal 9 X 9 X 9 example
...........0
..........1.1
.........1.0.1
........0.1.1.1
.......0.0.1.0.0
......0.0.0.0.0.0
.....1.1.1.0.1.1.1
....1.0.1.0.0.1.0.1
...0.1.1.1.0.1.1.1.0

Crossrefs

Sequence in context: A155409 A155406 A155352 * A155315 A155323 A121091

Adjacent sequences: A155358 A155359 A155360 * A155362 A155363 A155364

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved