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%I #5 Mar 31 2012 12:37:14
%S 13,169,1153,7675,55063,397221,2841311,20294131,145066667,1037297447,
%T 7416956341,53030329081,379156174051,2710908891177,19382663085405,
%U 138583595369137,990854370992397,7084476762966115,50653072024038803
%N Number of nX4 0..1 arrays avoiding 0 0 0 horizontally and 1 0 1 vertically
%C Column 4 of A206871
%H R. H. Hardin, <a href="/A206867/b206867.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 7*a(n-1) -9*a(n-2) +59*a(n-3) +77*a(n-4) +95*a(n-5) +211*a(n-6) -354*a(n-7) -1120*a(n-8) -115*a(n-9) +1235*a(n-10) +539*a(n-11) -820*a(n-12) -522*a(n-13) -28*a(n-14) +7*a(n-15) +88*a(n-16) +54*a(n-17) +14*a(n-18) +13*a(n-19) +a(n-20) +a(n-21)
%e Some solutions for n=4
%e ..0..0..1..0....1..0..0..1....0..1..1..0....0..0..1..0....0..1..1..0
%e ..1..1..0..1....1..1..0..0....1..1..0..0....0..0..1..0....0..1..1..1
%e ..1..0..0..1....1..0..1..0....0..1..0..0....1..1..0..0....0..1..0..1
%e ..0..0..1..1....1..0..0..1....0..1..1..0....1..1..0..0....1..0..0..1
%K nonn
%O 1,1
%A _R. H. Hardin_ Feb 13 2012
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