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A155253 Number of ways to place zero or more nonadjacent 1,1 2,0 2,1 2,2 3,1 4,1 polyhexes in any orientation on a planar nXnXn triangular grid. 0
1, 13, 37, 73, 378, 3421, 36342, 293256, 3406317, 59935388, 1419179921, 37034743264, 1162832741191, 48524067272860 (list; graph; refs; listen; history; text; internal format)
OFFSET

4,2

LINKS

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

EXAMPLE

Maximal 11 X 11 X 11 example

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

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

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

..........0.0.1.0

.........1.0.0.1.0

........1.1.1.0.0.0

.......0.0.1.0.0.0.0

......0.1.0.1.0.0.1.0

.....1.1.0.0.0.1.0.1.1

....0.1.0.1.1.1.1.0.1.0

...0.1.1.0.0.1.0.0.1.1.0

CROSSREFS

Sequence in context: A155304 A183454 A155265 * A155234 A222964 A089114

Adjacent sequences:  A155250 A155251 A155252 * A155254 A155255 A155256

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 22 2009

STATUS

approved

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Last modified November 23 04:28 EST 2014. Contains 249839 sequences.