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A155420 Number of ways to place zero or more nonadjacent 1,1 2,0 2,1 3,2 4,2 5,3 5,4 6,3 polyhexes in any orientation on a planar n X n X n triangular grid. 0
1, 7, 19, 37, 67, 234, 1126, 6422, 32270, 161586, 990365, 7766402, 74447984, 789199485, 8923308481 (list; graph; refs; listen; history; text; internal format)
OFFSET

6,2

LINKS

Table of n, a(n) for n=6..20.

EXAMPLE

Maximal 11 X 11 X 11 example

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

............0.0

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

..........0.0.1.1

.........0.1.1.0.0

........1.1.0.0.0.1

.......0.0.1.0.1.1.0

......1.0.0.0.0.0.1.0

.....0.1.1.0.1.0.1.0.0

....0.1.0.1.1.0.0.1.1.0

...0.0.0.0.0.1.0.1.0.0.0

CROSSREFS

Sequence in context: A288021 A155394 A155412 * A155434 A155378 A155438

Adjacent sequences:  A155417 A155418 A155419 * A155421 A155422 A155423

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 22 2009

STATUS

approved

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Last modified August 19 16:39 EDT 2022. Contains 356229 sequences. (Running on oeis4.)