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A227439 Number of n X 3 0,1 arrays indicating 2 X 2 subblocks of some larger (n+1) X 4 binary array having two adjacent 1's and two adjacent 0's. 1
8, 62, 457, 3346, 24568, 180575, 1327102, 9752326, 71665377, 526639966, 3870071062, 28439626805, 208991567034, 1535796359850, 11285960160481, 82936058669080, 609464300937756, 4478712154302465, 32912284659166926 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A227442.

LINKS

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

FORMULA

Empirical: a(n) = 11*a(n-1) -36*a(n-2) +79*a(n-3) -87*a(n-4) -7*a(n-5) +159*a(n-6) -206*a(n-7) +127*a(n-8) -31*a(n-9).

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Sequence in context: A198690 A056054 A167251 * A144143 A284225 A229011

Adjacent sequences:  A227436 A227437 A227438 * A227440 A227441 A227442

KEYWORD

nonn

AUTHOR

R. H. Hardin Jul 11 2013

STATUS

approved

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Last modified September 27 08:16 EDT 2021. Contains 347689 sequences. (Running on oeis4.)