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A208686 Number of nX6 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 1 1 and 1 0 1 vertically.

%I A208686 #7 Jul 22 2025 21:27:41
%S A208686 26,676,2430,11727,66094,301035,1332721,6219706,28669412,130450900,
%T A208686 599156271,2760581304,12692272021,58421183145,269289045586,
%U A208686 1241270953000,5722274656706,26389387599127,121715139738150,561405501868311
%N A208686 Number of nX6 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 1 1 and 1 0 1 vertically.
%C A208686 Column 6 of A208688
%H A208686 R. H. Hardin, <a href="/A208686/b208686.txt">Table of n, a(n) for n = 1..210</a>
%F A208686 Empirical: a(n) = 6*a(n-1) -7*a(n-2) +31*a(n-3) -128*a(n-4) -30*a(n-5) -116*a(n-6) +788*a(n-7) +798*a(n-8) +678*a(n-9) -2778*a(n-10) -1872*a(n-11) -1842*a(n-12) +3336*a(n-13) +1554*a(n-14) +378*a(n-15) -2736*a(n-16) +912*a(n-17) +312*a(n-18) +1590*a(n-19) -540*a(n-20) -228*a(n-21) -222*a(n-22) +210*a(n-23) -86*a(n-24) +24*a(n-25) -38*a(n-26) +8*a(n-27) -a(n-28) -a(n-30) +a(n-31)
%e A208686 Some solutions for n=4
%e A208686 ..1..1..0..1..1..0....1..1..0..1..0..1....1..1..0..1..1..1....1..0..1..1..1..1
%e A208686 ..0..1..0..1..0..1....0..1..1..1..1..1....1..1..0..1..1..0....1..0..1..0..1..0
%e A208686 ..0..1..0..1..0..0....0..1..0..1..0..1....0..1..1..1..0..0....1..0..1..0..1..0
%e A208686 ..1..0..1..0..1..0....0..1..0..1..0..1....0..1..0..1..0..1....0..1..0..1..1..1
%K A208686 nonn
%O A208686 1,1
%A A208686 _R. H. Hardin_ Mar 01 2012