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Number of nX4 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 1 0 and 1 1 1 vertically
1

%I #5 Mar 31 2012 12:37:20

%S 9,81,164,400,824,1940,4200,9276,21004,46026,102674,228630,506868,

%T 1128070,2505156,5569740,12380188,27502690,61145106,135886522,

%U 301975112,671190932,1491685306,3315241202,7368059728,16375432824,36394465410

%N Number of nX4 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 1 0 and 1 1 1 vertically

%C Column 4 of A207879

%H R. H. Hardin, <a href="/A207875/b207875.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-2) +7*a(n-3) +4*a(n-4) -3*a(n-5) -17*a(n-6) -5*a(n-7) +7*a(n-8) +2*a(n-9) -13*a(n-10) -a(n-11) -2*a(n-12) for n>14

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Feb 21 2012