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Number of nX3 0..1 arrays avoiding 0 0 1 horizontally and 0 1 1 vertically
2

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

%S 7,49,230,1020,4120,16109,61003,227197,834806,3041436,11009856,

%T 39680145,142545383,510891025,1827957230,6532356532,23322885552,

%U 83216416445,296774223739,1058010185133,3770863749966,13437211488900,47875876583016

%N Number of nX3 0..1 arrays avoiding 0 0 1 horizontally and 0 1 1 vertically

%C Column 3 of A206785

%H R. H. Hardin, <a href="/A206780/b206780.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 7*a(n-1) -10*a(n-2) -23*a(n-3) +57*a(n-4) +6*a(n-5) -75*a(n-6) +21*a(n-7) +34*a(n-8) -13*a(n-9) -5*a(n-10) +2*a(n-11)

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Feb 12 2012