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A206088 Number of (n+1) X 3 0..2 arrays with every 2 X 3 or 3 X 2 subblock having exactly two counterclockwise and two clockwise edge increases. 1
270, 780, 2016, 5952, 17976, 54432, 165936, 504912, 1538496, 4687392, 14278656, 43507872, 132544416, 403832352, 1230343776, 3748436832, 11420384736, 34794057312, 106006675296, 322968189792, 983980623456, 2997875890272 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A206094.

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) + 6*a(n-2) + 4*a(n-3) - 10*a(n-4) for n>6.

Empirical g.f.: 6*x*(45 + 85*x - 64*x^2 - 304*x^3 - 82*x^4 + 80*x^5) / ((1 - x)*(1 - 6*x^2 - 10*x^3)). - Colin Barker, Jun 13 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Cf. A206094.

Sequence in context: A292766 A180151 A278130 * A029770 A028529 A109025

Adjacent sequences:  A206085 A206086 A206087 * A206089 A206090 A206091

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 03 2012

STATUS

approved

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Last modified April 15 13:13 EDT 2021. Contains 342977 sequences. (Running on oeis4.)