A155229 - OEIS

A155229

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

1, 4, 10, 19, 54, 346, 1831, 9221, 66079, 717157, 8272905, 104484553, 1712695513, 36940968544, 931841300560, 27497789520438, 1009266090959240, 46345568210962143

(list; graph; refs; listen; history; text; internal format)

OFFSET

3,2

LINKS

Table of n, a(n) for n=3..20.

EXAMPLE

Maximal 11 X 11 X 11 example

.............0

............1.0

...........1.1.1

..........0.0.1.0

.........0.0.0.0.0

........1.1.0.0.0.1

.......0.1.0.0.1.1.1

......0.1.1.0.0.1.0.0

.....1.0.0.0.1.0.0.1.1

....1.1.1.0.1.1.1.0.1.0

...0.0.1.0.0.0.1.0.1.1.0

CROSSREFS

Sequence in context: A251176 A155428 A155383 * A155220 A300018 A268221

Adjacent sequences: A155226 A155227 A155228 * A155230 A155231 A155232

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 22 2009

STATUS

approved