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A221346 Number of 3Xn arrays of occupancy after each element stays put or moves to some horizontal, diagonal or antidiagonal neighbor, with no occupancy greater than 2 1
1, 137, 2856, 66077, 1534835, 36054361, 849482126, 20037479191, 472778990849, 11155734923302, 263229189709284, 6210988381194727, 146547761557950631, 3457733626802911867, 81582980136833112390, 1924884328527038591459 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row 3 of A221345

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..18

EXAMPLE

Some solutions for n=3

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

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

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

CROSSREFS

Sequence in context: A215864 A190307 A094488 * A138348 A278175 A261973

Adjacent sequences:  A221343 A221344 A221345 * A221347 A221348 A221349

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 11 2013

STATUS

approved

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Last modified June 7 02:48 EDT 2020. Contains 334836 sequences. (Running on oeis4.)