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A244694 Number of length n+4 0..2 arrays with no five consecutive elements with pattern ababa or abbba (with a!=b) and new values 0..2 introduced in 0..2 order. 1
39, 111, 317, 908, 2602, 7459, 21383, 61302, 175745, 503841, 1444456, 4141097, 11872072, 34035934, 97577307, 279743489, 801994051, 2299229415, 6591639797, 18897511895, 54177104154, 155319844796, 445285043640, 1276583622333 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-1) - a(n-3) - a(n-5) + a(n-6) - a(n-7).

Empirical g.f.: x*(39 - 6*x - 16*x^2 - 4*x^3 - 11*x^4 + 9*x^5 - 14*x^6) / ((1 - x)*(1 + x)*(1 - 3*x + x^2 - 2*x^3 + x^4 - x^5)). - Colin Barker, Nov 03 2018

EXAMPLE

Some solutions for n=6:

..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0

..1....1....1....1....1....0....1....1....0....1....0....0....1....0....1....1

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

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

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

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

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

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

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

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

CROSSREFS

Column 2 of A244702.

Sequence in context: A276401 A044226 A044607 * A008878 A249301 A239562

Adjacent sequences:  A244691 A244692 A244693 * A244695 A244696 A244697

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jul 04 2014

STATUS

approved

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Last modified June 4 11:05 EDT 2020. Contains 334825 sequences. (Running on oeis4.)