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A155290 Number of ways to place zero or more nonadjacent 1,0 1,1 2,1 3,1 4,2 5,2 polyhexes in any orientation on a planar nXnXn triangular grid. 0
1, 7, 25, 64, 265, 1577, 11987, 107928, 1180991, 15701569, 264954393, 5697447937, 151647215266 (list; graph; refs; listen; history; text; internal format)
OFFSET

4,2

LINKS

Table of n, a(n) for n=4..16.

EXAMPLE

Maximal 11 X 11 X 11 example

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

............0.1

...........0.1.1

..........1.1.0.0

.........1.0.0.1.1

........0.0.0.0.1.0

.......1.0.1.0.1.0.1

......1.0.0.1.0.1.0.1

.....0.1.0.1.0.1.0.1.0

....0.1.0.0.1.0.0.0.1.0

...0.1.1.0.1.1.0.0.1.1.0

CROSSREFS

Sequence in context: A001845 A127765 A155305 * A056685 A299262 A001296

Adjacent sequences:  A155287 A155288 A155289 * A155291 A155292 A155293

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 22 2009

STATUS

approved

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Last modified February 17 23:47 EST 2018. Contains 299297 sequences. (Running on oeis4.)