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A155404 Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 2,2 3,0 3,1 4,0 4,2 polyhexes in any orientation on a planar nXnXn triangular grid. 0
1, 4, 10, 22, 40, 135, 446, 2376, 12035, 65714, 364923, 2734456, 23495580, 245925457, 2738475904, 35447846068, 514467522739 (list; graph; refs; listen; history; text; internal format)
OFFSET

4,2

LINKS

Table of n, a(n) for n=4..20.

EXAMPLE

Maximal 9 X 9 X 9 example

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

..........1.0

.........0.1.1

........1.1.0.0

.......1.0.1.0.1

......0.0.0.0.0.1

.....1.0.1.0.1.1.0

....0.1.1.0.0.0.1.1

...1.1.0.1.1.0.1.0.1

CROSSREFS

Sequence in context: A061777 A298030 A155369 * A155360 A155382 A155287

Adjacent sequences:  A155401 A155402 A155403 * A155405 A155406 A155407

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 22 2009

STATUS

approved

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Last modified September 23 19:03 EDT 2021. Contains 347617 sequences. (Running on oeis4.)