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A183814 1/81 the number of (n+1) X 4 0..2 arrays with no 2 X 2 subblock being a reflection across the shared element pair of any horizontal or vertical neighbor. 1

%I

%S 64,3256,163208,8231592,414246824,20864057480,1050517114472,

%T 52900274426120,2663752907479720,134133403972622152,

%U 6754253376412941416,340109468142471752968,17126149629153540430376,862384378029691966195144

%N 1/81 the number of (n+1) X 4 0..2 arrays with no 2 X 2 subblock being a reflection across the shared element pair of any horizontal or vertical neighbor.

%C Column 3 of A183819.

%H R. H. Hardin, <a href="/A183814/b183814.txt">Table of n, a(n) for n = 1..41</a>

%F Empirical: a(n) = 43*a(n-1) + 560*a(n-2) - 10054*a(n-3) + 24480*a(n-4) + 45920*a(n-5).

%F Empirical g.f.: 8*x*(8 + 63*x - 1580*x^2 + 4218*x^3 + 7624*x^4) / (1 - 43*x - 560*x^2 + 10054*x^3 - 24480*x^4 - 45920*x^5). - _Colin Barker_, Apr 04 2018

%e Some solutions with upper left block zero for 3 X 4:

%e ..0..0..0..1....0..0..0..1....0..0..0..2....0..0..2..2....0..0..0..2

%e ..0..0..1..1....0..0..1..2....0..0..1..1....0..0..1..0....0..0..2..0

%e ..2..1..1..1....2..0..2..1....2..2..2..1....2..0..0..1....0..2..0..0

%Y Cf. A183819.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 07 2011

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Last modified July 22 10:34 EDT 2019. Contains 325219 sequences. (Running on oeis4.)