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A155315 Number of ways to place zero or more nonadjacent 1,0 2,0 2,1 2,2 3,0 3,1 4,2 polyhexes in any orientation on a planar nXnXn triangular grid. 0
1, 7, 19, 37, 61, 503, 4407, 23093, 93285, 817543, 14192015, 204195517, 2243020429, 32774055967, 863753860919, 27738606644581, 798910205504069, 24797177099870103 (list; graph; refs; listen; history; text; internal format)
OFFSET

4,2

COMMENTS

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

LINKS

Table of n, a(n) for n=4..21.

EXAMPLE

Maximal 9 X 9 X 9 example

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

..........1.0

.........1.1.1

........1.1.0.0

.......0.0.1.0.0

......0.0.0.0.0.1

.....1.1.1.0.1.1.1

....0.1.1.0.0.0.1.1

...0.1.0.1.0.0.1.0.0

CROSSREFS

Sequence in context: A155406 A155352 A155361 * A155323 A121091 A213489

Adjacent sequences:  A155312 A155313 A155314 * A155316 A155317 A155318

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 22 2009

STATUS

approved

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Last modified October 1 14:19 EDT 2022. Contains 357149 sequences. (Running on oeis4.)