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A166199 Number of nXnXn triangular nonnegative integer arrays, symmetric under 120 degree rotation, with all sums of an element and its neighbors <= 4 1
1, 5, 2, 4, 25, 64, 249, 2376, 9030, 76249, 1598732, 10091912, 165533393, 6511049130, 90909213960, 2908246084285, 219536965840260, 5801006454694383 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..17.

EXAMPLE

Some solutions for n=4

.....0........1........1........1........1........2........2........3...

....0.0......0.0......0.0......0.1......0.0......1.0......0.0......0.0..

...0.3.0....0.2.0....0.3.0....1.1.0....0.0.0....0.0.1....0.0.0....0.1.0.

..0.0.0.0..1.0.0.1..1.0.0.1..1.0.1.1..1.0.0.1..2.1.0.2..2.0.0.2..3.0.0.3

------

.....1........0........4........1........1........2........2........0...

....1.0......0.0......0.0......1.0......0.1......0.1......0.0......0.1..

...0.1.1....0.1.0....0.0.0....0.0.1....1.0.0....1.0.0....0.1.0....1.0.0.

..1.1.0.1..0.0.0.0..4.0.0.4..1.1.0.1..1.0.1.1..2.0.1.2..2.0.0.2..0.0.1.0

CROSSREFS

Sequence in context: A264991 A088507 A050001 * A324860 A008566 A111129

Adjacent sequences:  A166196 A166197 A166198 * A166200 A166201 A166202

KEYWORD

nonn

AUTHOR

R. H. Hardin Oct 09 2009

STATUS

approved

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Last modified August 7 08:55 EDT 2020. Contains 336274 sequences. (Running on oeis4.)