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A155356 Number of ways to place zero or more nonadjacent 0,0 1,0 1,1 2,0 2,1 2,2 3,1 3,2 polyhexes in any orientation on a planar n X n X n triangular grid. 0
1, 4, 13, 28, 49, 268, 2207, 13527, 65442, 532199, 7461240, 113949026, 1537124321, 25756946558, 635120397887, 20097790938202, 675874617024695, 25863870998834477, 1279264911762340761 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,2

COMMENTS

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

LINKS

Table of n, a(n) for n=3..21.

EXAMPLE

Maximal 10 X 10 X 10 example

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

...........1.1

..........1.1.1

.........0.1.1.1

........0.0.0.0.0

.......0.0.1.1.0.0

......0.0.1.1.1.0.0

.....1.1.0.1.1.0.1.1

....1.1.1.0.1.0.1.1.1

...1.1.1.0.0.0.1.1.1.0

CROSSREFS

Sequence in context: A155435 A155371 A155355 * A060488 A054968 A087035

Adjacent sequences:  A155353 A155354 A155355 * A155357 A155358 A155359

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 22 2009

STATUS

approved

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Last modified November 27 12:51 EST 2021. Contains 349394 sequences. (Running on oeis4.)