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A210269 Half the number of (n+1) X 2 0..2 arrays with every 2 X 2 subblock having two or three distinct clockwise edge differences. 1
35, 273, 2130, 16620, 129684, 1011912, 7895856, 61610640, 480742176, 3751187136, 29270169408, 228392449152, 1782125347584, 13905760747776, 108505376592384, 846657508568064, 6606390939571200, 51549062997460992, 402232613876871168 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A210276.

LINKS

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

FORMULA

Empirical: a(n) = 8*a(n-1) - 12*a(n-3).

Empirical g.f.: x*(35 - 7*x - 54*x^2) / (1 - 8*x + 12*x^3). - Colin Barker, Jul 15 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Cf. A210276.

Sequence in context: A251931 A267627 A210276 * A219575 A219711 A055658

Adjacent sequences:  A210266 A210267 A210268 * A210270 A210271 A210272

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 19 2012

STATUS

approved

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Last modified October 16 01:52 EDT 2021. Contains 348034 sequences. (Running on oeis4.)