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A208557 Number of 5 X n 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 0 1 1 vertically. 1

%I #8 Jul 04 2018 08:54:39

%S 12,144,420,2508,10080,50052,221340,1042416,4742628,21989868,

%T 100900800,465657348,2142175548,9872120016,45450619620,209366048652,

%U 964140982560,4440671206788,20451041895900,94190120555184,433792784654052

%N Number of 5 X n 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 0 1 1 vertically.

%C Row 5 of A208555.

%H R. H. Hardin, <a href="/A208557/b208557.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) + 17*a(n-2) + 6*a(n-3) - 36*a(n-4).

%F Empirical g.f.: 12*x*(1 + 11*x + 6*x^2 - 36*x^3) / ((1 + x - 3*x^2)*(1 - 2*x - 12*x^2)). - _Colin Barker_, Jul 04 2018

%e Some solutions for n=4:

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

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

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

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

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

%Y Cf. A208555.

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 28 2012

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Last modified April 23 20:33 EDT 2024. Contains 371916 sequences. (Running on oeis4.)