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A207121 Number of nX6 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 0 1 and 0 1 1 vertically.

%I A207121 #7 Jul 22 2025 20:03:03
%S A207121 21,441,2499,14161,49861,175561,475984,1290496,2958144,6780816,
%T A207121 13816824,28153636,52561236,98128836,171205398,298702089,493723461,
%U A207121 816073489,1290571359,2040961329,3110933397,4741837321,7005780418,10350620644
%N A207121 Number of nX6 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 0 1 and 0 1 1 vertically.
%C A207121 Column 6 of A207123
%H A207121 R. H. Hardin, <a href="/A207121/b207121.txt">Table of n, a(n) for n = 1..210</a>
%F A207121 Empirical: a(n) = 2*a(n-1) +10*a(n-2) -22*a(n-3) -44*a(n-4) +110*a(n-5) +110*a(n-6) -330*a(n-7) -165*a(n-8) +660*a(n-9) +132*a(n-10) -924*a(n-11) +924*a(n-13) -132*a(n-14) -660*a(n-15) +165*a(n-16) +330*a(n-17) -110*a(n-18) -110*a(n-19) +44*a(n-20) +22*a(n-21) -10*a(n-22) -2*a(n-23) +a(n-24)
%e A207121 Some solutions for n=4
%e A207121 ..0..1..1..1..0..1....0..0..0..0..0..0....1..0..1..1..1..0....1..0..1..1..1..0
%e A207121 ..0..0..0..0..0..0....1..0..0..0..0..0....0..1..1..1..1..0....0..1..1..0..1..1
%e A207121 ..0..0..0..0..0..0....0..0..0..0..0..0....0..0..0..0..0..0....0..0..0..0..0..0
%e A207121 ..0..0..0..0..0..0....0..0..0..0..0..0....0..0..0..0..0..0....0..0..0..0..0..0
%K A207121 nonn
%O A207121 1,1
%A A207121 _R. H. Hardin_ Feb 15 2012