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A155331 Number of ways to place zero or more nonadjacent 1,0 1,1 2,0 3,0 4,0 5,0 6,1 polyhexes in any orientation on a planar nXnXn triangular grid. 0
1, 4, 13, 28, 131, 616, 2577, 12364, 77884, 560672, 4490012, 45293635, 525483762 (list; graph; refs; listen; history; text; internal format)
OFFSET

5,2

LINKS

Table of n, a(n) for n=5..17.

EXAMPLE

Maximal 9 X 9 X 9 example

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

..........1.1

.........1.0.0

........1.0.1.1

.......1.0.0.0.1

......1.0.0.0.0.1

.....0.1.0.0.0.0.1

....1.0.0.0.0.1.0.1

...0.1.1.1.1.1.0.1.0

CROSSREFS

Sequence in context: A155238 A155320 A155279 * A155387 A155366 A340002

Adjacent sequences:  A155328 A155329 A155330 * A155332 A155333 A155334

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 22 2009

STATUS

approved

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Last modified May 7 09:58 EDT 2021. Contains 343649 sequences. (Running on oeis4.)