A155357 Number of ways to place zero or more nonadjacent 1,0 1,1 2,0 2,1 3,0 3,1 4,0 4,1 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 37, 209, 927, 4735, 37071, 286745, 2579963, 31707495, 434469270, 7173015390, 147194484531, 3498010136593

Offset

4,2

Comments

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

Links

Table of n, a(n) for n=4..18.

Example

Maximal 11 X 11 X 11 example
.............0
............0.0
...........0.1.1
..........0.0.1.1
.........1.1.0.1.1
........1.1.0.0.1.1
.......1.1.0.0.0.0.0
......1.1.0.1.1.0.1.1
.....0.0.0.0.1.1.0.1.1
....1.1.1.1.0.1.1.0.1.1
...0.1.1.1.1.0.1.1.0.1.1

Crossrefs

Sequence in context: A155332 A155388 A155367 * A155248 A027452 A051937

Adjacent sequences: A155354 A155355 A155356 * A155358 A155359 A155360

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved