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A209945 Half the number of (n+1)X3 0..2 arrays with every 2X2 subblock having at most one duplicate clockwise edge difference 1
258, 4975, 95794, 1845126, 35537484, 684469520, 13183187396, 253914272972, 4890505660356, 94193393412380, 1814208180084540, 34942486067121236, 673008393916430500, 12962452003109036652, 249662802833380927452 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A209951

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 20*a(n-1) +25*a(n-2) -708*a(n-3) -1034*a(n-4) +2172*a(n-5) -160*a(n-6) -320*a(n-7)

EXAMPLE

Some solutions for n=4

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

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

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

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

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

CROSSREFS

Sequence in context: A252264 A202892 A158230 * A233306 A282060 A301546

Adjacent sequences:  A209942 A209943 A209944 * A209946 A209947 A209948

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 16 2012

STATUS

approved

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Last modified May 19 13:24 EDT 2022. Contains 353833 sequences. (Running on oeis4.)