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A206014 Number of (n+1) X 2 0..3 arrays with the number of clockwise edge increases in every 2 X 2 subblock unequal to the number of counterclockwise edge increases. 1
104, 680, 4440, 29000, 189400, 1237000, 8079000, 52765000, 344615000, 2250725000, 14699775000, 96006125000, 627028375000, 4095203125000, 26746299375000, 174683528125000, 1140880634375000, 7451238453125000, 48664998609375000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A206021.

LINKS

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

FORMULA

Empirical: a(n) = 5*a(n-1) + 10*a(n-2).

Empirical g.f.: 8*x*(13 + 20*x) / (1 - 5*x - 10*x^2). - Colin Barker, Jun 13 2018

EXAMPLE

Some solutions for n=3:

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

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

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

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

CROSSREFS

Cf. A206021.

Sequence in context: A250676 A250677 A206021 * A106298 A337145 A230028

Adjacent sequences: A206011 A206012 A206013 * A206015 A206016 A206017

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 02 2012

STATUS

approved

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Last modified December 8 07:38 EST 2022. Contains 358691 sequences. (Running on oeis4.)