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A185762 Number of (n+1) X 3 binary arrays with no 2 X 2 subblock trace equal to any horizontal or vertical neighbor 2 X 2 subblock trace. 1
40, 120, 368, 1128, 3456, 10592, 32456, 99464, 304792, 934032, 2862248, 8771232, 26878752, 82368392, 252412136, 773501240, 2370342448, 7263762024, 22259317952, 68212232544, 209031902280, 640564615496, 1962968261720, 6015387856976 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A185769.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

FORMULA

Empirical: a(n) = a(n-1) + 6*a(n-2) + a(n-3).

Empirical g.f.: 8*x*(5 + 10*x + x^2) / (1 - x - 6*x^2 - x^3). - Colin Barker, Apr 16 2018

EXAMPLE

Some solutions for 5 X 3.

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

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

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

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

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

CROSSREFS

Cf. A185769.

Sequence in context: A234921 A199807 A199810 * A234914 A043470 A044291

Adjacent sequences:  A185759 A185760 A185761 * A185763 A185764 A185765

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 03 2011

STATUS

approved

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Last modified September 30 06:13 EDT 2022. Contains 357099 sequences. (Running on oeis4.)