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A207678 Number of n X 4 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 1 1 1 vertically.

%I A207678 #7 Dec 29 2023 10:03:43
%S A207678 9,81,164,436,1030,2032,4174,8266,16060,30670,57888,109188,202628,
%T A207678 375252,692182,1267634,2319308,4224978,7679364,13935174,25221442,
%U A207678 45611766,82350810,148518712,267668550,481894280,867169926,1559501878,2803131788
%N A207678 Number of n X 4 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 1 1 1 vertically.
%C A207678 Column 4 of A207682.
%H A207678 R. H. Hardin, <a href="/A207678/b207678.txt">Table of n, a(n) for n = 1..210</a>
%F A207678 Empirical: a(n) = 2*a(n-1) +2*a(n-2) +a(n-3) -12*a(n-4) -3*a(n-5) +27*a(n-7) +8*a(n-8) -2*a(n-9) -33*a(n-10) -15*a(n-11) +19*a(n-13) +23*a(n-14) -4*a(n-15) +a(n-16) -19*a(n-17) +4*a(n-18) -4*a(n-19) +7*a(n-20) -a(n-21) +a(n-22) -a(n-23) for n>28.
%e A207678 Some solutions for n=4
%e A207678 ..1..1..0..0....1..0..0..1....1..1..1..0....1..0..0..1....1..0..0..1
%e A207678 ..0..1..1..1....0..1..0..0....0..0..1..1....1..1..1..1....0..1..1..0
%e A207678 ..1..0..0..1....1..0..0..1....0..1..0..0....0..0..1..0....1..1..0..0
%e A207678 ..1..1..0..0....0..1..0..0....0..0..1..1....0..1..0..0....0..0..1..0
%Y A207678 Cf. A207682.
%K A207678 nonn
%O A207678 1,1
%A A207678 _R. H. Hardin_, Feb 19 2012