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A208029 Number of 4 X n 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 0 and 1 0 1 vertically. 1
9, 81, 279, 1377, 5895, 26685, 118179, 527913, 2350215, 10476981, 46680363, 208028817, 926993439, 4130894781, 18407971395, 82029484089, 365538508695, 1628908337349, 7258719524571, 32346212936481, 144140772230991 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 4 of A208028.

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) + 11*a(n-2) + 2*a(n-3) - 10*a(n-4).

Empirical g.f.: 9*x*(1 - x)*(1 + 8*x + 10*x^2) / (1 - 2*x - 11*x^2 - 2*x^3 + 10*x^4). - Colin Barker, Jun 26 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

CROSSREFS

Cf. A208028.

Sequence in context: A207463 A207914 A208040 * A208160 A207956 A207238

Adjacent sequences:  A208026 A208027 A208028 * A208030 A208031 A208032

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 22 2012

STATUS

approved

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Last modified October 6 00:49 EDT 2022. Contains 357261 sequences. (Running on oeis4.)