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A207704 Number of 3Xn 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 1 1 0 vertically.

%I A207704 #7 Jul 22 2025 20:41:51
%S A207704 6,36,102,289,1071,3969,13230,44100,153090,531441,1815939,6205081,
%T A207704 21332924,73342096,251550372,862773129,2961885201,10168100569,
%U A207704 34894442176,119749218304,411007092416,1410671672089,4841491994817
%N A207704 Number of 3Xn 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 1 1 0 vertically.
%C A207704 Row 3 of A207703
%H A207704 R. H. Hardin, <a href="/A207704/b207704.txt">Table of n, a(n) for n = 1..210</a>
%F A207704 Empirical: a(n) = 2*a(n-1) +10*a(n-3) +25*a(n-4) -2*a(n-5) +4*a(n-6) -28*a(n-7) -68*a(n-8) -2*a(n-9) +4*a(n-10) +10*a(n-11) +25*a(n-12) +2*a(n-13) -a(n-16)
%e A207704 Some solutions for n=4
%e A207704 ..0..0..1..1....1..1..1..1....1..0..1..1....0..1..1..1....1..1..1..1
%e A207704 ..1..1..1..1....0..0..1..1....0..0..1..1....1..0..0..1....1..1..0..1
%e A207704 ..1..1..1..1....0..1..1..1....0..0..1..1....0..0..1..1....1..1..1..1
%K A207704 nonn
%O A207704 1,1
%A A207704 _R. H. Hardin_ Feb 19 2012