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%I #5 Mar 31 2012 12:37:20
%S 9,81,271,1309,5371,23637,101069,438103,1887667,8151773,35161937,
%T 151744767,654767065,2825582407,12192964863,52615498559,227045509685,
%U 979746980809,4227807834119,18243882203687,78726167982599
%N Number of nX4 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 1 0 and 1 0 1 vertically
%C Column 4 of A207918
%H R. H. Hardin, <a href="/A207914/b207914.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 6*a(n-1) -12*a(n-2) +17*a(n-3) +5*a(n-4) +51*a(n-5) +36*a(n-6) -399*a(n-7) +554*a(n-8) -625*a(n-9) -854*a(n-10) -4016*a(n-11) +210*a(n-12) +9416*a(n-13) +9774*a(n-14) +4886*a(n-15) -6673*a(n-16) -6888*a(n-17) -6416*a(n-18) -2847*a(n-19) -607*a(n-20) +1513*a(n-21) +1902*a(n-22) +1033*a(n-23) +100*a(n-24) -185*a(n-25) -162*a(n-26) -18*a(n-27) +8*a(n-29)
%e Some solutions for n=4
%e ..1..1..1..1....1..0..0..1....0..0..1..1....0..0..1..0....0..1..1..1
%e ..1..1..1..1....1..1..1..1....1..0..0..1....1..1..0..0....1..0..0..1
%e ..1..1..1..1....1..1..1..1....1..1..0..0....1..1..0..0....1..0..0..1
%e ..1..1..0..0....1..0..0..1....1..1..0..0....0..1..0..0....0..0..1..1
%K nonn
%O 1,1
%A _R. H. Hardin_ Feb 21 2012
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