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A207786 Number of 4Xn 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 0 and 1 0 1 vertically.

%I A207786 #8 Jul 22 2025 20:50:48
%S A207786 9,81,253,791,2173,5241,12567,28101,61397,131083,272789,560651,
%T A207786 1133751,2266643,4487109,8799557,17130019,33113221,63623053,121586791,
%U A207786 231212705,437760595,825496887,1550995293,2904417145,5422206945,10094193051
%N A207786 Number of 4Xn 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 0 and 1 0 1 vertically.
%C A207786 Row 4 of A207785
%H A207786 R. H. Hardin, <a href="/A207786/b207786.txt">Table of n, a(n) for n = 1..210</a>
%F A207786 Empirical: a(n) = 4*a(n-1) -13*a(n-3) -6*a(n-4) +41*a(n-5) +10*a(n-6) -57*a(n-7) -32*a(n-8) +66*a(n-9) +18*a(n-10) -31*a(n-11) +14*a(n-13) -30*a(n-14) +4*a(n-15) +32*a(n-16) -13*a(n-17) -12*a(n-18) +a(n-19) +6*a(n-20) -9*a(n-21) +12*a(n-22) -2*a(n-23) -3*a(n-25) +2*a(n-26) -2*a(n-27) +a(n-28)
%e A207786 Some solutions for n=4
%e A207786 ..1..1..1..1....1..1..0..0....0..0..1..0....0..1..0..1....1..1..1..0
%e A207786 ..0..1..0..1....0..1..0..1....1..0..1..0....0..1..0..1....0..1..0..0
%e A207786 ..0..1..0..0....0..0..1..0....0..1..0..1....1..0..1..0....0..1..0..1
%e A207786 ..1..0..1..0....1..0..1..0....0..1..0..0....1..0..1..0....1..0..1..0
%K A207786 nonn
%O A207786 1,1
%A A207786 _R. H. Hardin_ Feb 20 2012