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A207560 Number of n X 4 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 1 1 and 1 1 0 vertically. 1
9, 81, 241, 636, 2135, 6709, 23276, 78733, 277781, 973608, 3477827, 12422849, 44780404, 161681185, 586480585, 2130883040, 7761845079, 28308582237, 103395253764, 377977638085, 1382951559309, 5062965194920, 18545296800603 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A207564.

LINKS

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

FORMULA

Empirical: a(n) = 7*a(n-1) -2*a(n-2) -73*a(n-3) +95*a(n-4) +258*a(n-5) -429*a(n-6) -357*a(n-7) +730*a(n-8) +125*a(n-9) -499*a(n-10) +70*a(n-11) +106*a(n-12) -30*a(n-13) for n>14.

EXAMPLE

Some solutions for n=4:

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

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

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

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

CROSSREFS

Sequence in context: A208014 A208556 A063824 * A207415 A207020 A207364

Adjacent sequences:  A207557 A207558 A207559 * A207561 A207562 A207563

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 18 2012

STATUS

approved

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Last modified June 25 22:13 EDT 2022. Contains 354868 sequences. (Running on oeis4.)