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Number of 4Xn 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 1 1 and 1 1 0 vertically
1

%I #5 Mar 31 2012 12:37:18

%S 9,81,221,636,2234,6315,16812,47596,129150,337186,892181,2343529,

%T 6046508,15601217,40205083,102833093,262404045,669166152,1701139222,

%U 4316129307,10943611348,27709283328,70072708774,177098593806,447280003769

%N Number of 4Xn 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 1 1 and 1 1 0 vertically

%C Row 4 of A207564

%H R. H. Hardin, <a href="/A207565/b207565.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-1) -4*a(n-2) +10*a(n-3) -30*a(n-4) +10*a(n-5) -4*a(n-6) +54*a(n-7) +10*a(n-8) -22*a(n-9) -62*a(n-10) -10*a(n-11) +18*a(n-12) +32*a(n-13) +7*a(n-14) -6*a(n-15) -6*a(n-16)

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Feb 18 2012