A155217 - OEIS

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A155217

Number of ways to place zero or more nonadjacent 1,0 1,1 2,1 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 2, 5, 10, 39, 205, 1026, 7765, 81639, 968094, 15354634, 328541791, 8661897260, 294910384475, 13193215967675, 751461392973699, 54989669970520419, 5219343962387133501, 636712452891464320519, 99887383227114543133737

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..20.

EXAMPLE

Maximal 13 X 13 X 13 example

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

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

.............0.0.0

............1.0.1.1

...........1.1.0.1.0

..........0.0.0.0.0.1

.........1.0.1.1.0.1.1

........1.1.0.1.0.0.0.0

.......0.0.0.0.0.1.1.0.1

......1.1.0.1.1.0.1.0.1.1

.....0.1.0.0.1.0.0.0.0.0.0

....1.0.0.1.0.0.1.0.1.1.0.1

...1.1.0.1.1.0.1.1.0.1.0.1.1

CROSSREFS

Sequence in context: A018418 A363429 A290032 * A004143 A266162 A103036

Adjacent sequences: A155214 A155215 A155216 * A155218 A155219 A155220

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 22 2009

STATUS

approved