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A185791 Number of (n+1) X 3 binary arrays with no 2 X 2 subblock sum equal to any horizontal or vertical neighbor 2 X 2 subblock sum. 1
40, 96, 224, 576, 1408, 3456, 8320, 20864, 50816, 125312, 304768, 756096, 1844864, 4548992, 11110016, 27429248, 67069568, 165194112, 404309632, 995805568, 2438669952, 6000273792, 14703462016, 36167944576, 88660698752, 217982249344 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A185798.

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) + 2*a(n-2) + 16*a(n-4) - 16*a(n-5).

Empirical g.f.: 8*x*(5 + 7*x + 6*x^2 + 20*x^3 - 32*x^4) / (1 - x - 2*x^2 - 16*x^4 + 16*x^5). - Colin Barker, Apr 16 2018

EXAMPLE

Some solutions for 5 X 3:

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

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

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

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

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

CROSSREFS

Cf. A185798.

Sequence in context: A279689 A063310 A211493 * A092889 A235280 A235271

Adjacent sequences: A185788 A185789 A185790 * A185792 A185793 A185794

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 04 2011

STATUS

approved

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Last modified December 4 11:24 EST 2022. Contains 358556 sequences. (Running on oeis4.)