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%I #5 Mar 31 2012 12:37:22
%S 8,64,240,900,2400,6400,14000,30625,58800,112896,197568,345744,564480,
%T 921600,1425600,2205225,3267000,4840000,6921200,9897316,13741728,
%U 19079424,25836720,34987225,46373600,61465600,79968000,104040000
%N Number of 4Xn 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 0 1 and 1 0 1 vertically
%C Row 4 of A208142
%H R. H. Hardin, <a href="/A208143/b208143.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 2*a(n-1) +6*a(n-2) -14*a(n-3) -14*a(n-4) +42*a(n-5) +14*a(n-6) -70*a(n-7) +70*a(n-9) -14*a(n-10) -42*a(n-11) +14*a(n-12) +14*a(n-13) -6*a(n-14) -2*a(n-15) +a(n-16)
%e Some solutions for n=4
%e ..0..0..0..0....0..0..0..0....1..1..0..1....1..0..0..0....1..1..1..1
%e ..1..0..0..0....0..1..0..0....0..0..0..0....0..1..0..0....1..1..1..1
%e ..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....1..1..1..1
%e ..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....1..1..1..1
%K nonn
%O 1,1
%A _R. H. Hardin_ Feb 23 2012
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