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A155307 Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 3,0 3,1 4,0 polyhexes in any orientation on a planar nXnXn triangular grid. 0
1, 4, 13, 37, 146, 620, 2737, 17298, 136979, 1185666, 12752003, 161758550, 2364549128, 42702118766 (list; graph; refs; listen; history; text; internal format)
OFFSET

4,2

COMMENTS

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

LINKS

Table of n, a(n) for n=4..17.

EXAMPLE

Maximal 11 X 11 X 11 example

.............1

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

...........0.1.0

..........1.0.1.1

.........1.0.0.0.1

........0.1.0.0.0.0

.......1.1.0.0.1.1.0

......1.0.0.1.1.0.1.1

.....0.0.0.0.0.0.0.0.0

....1.1.0.1.1.0.0.1.1.0

...0.0.1.1.0.0.1.1.0.1.1

CROSSREFS

Sequence in context: A297391 A108489 A155375 * A155344 A155418 A155235

Adjacent sequences:  A155304 A155305 A155306 * A155308 A155309 A155310

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 22 2009

STATUS

approved

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Last modified July 15 20:24 EDT 2019. Contains 325056 sequences. (Running on oeis4.)