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A207689 Number of n X 4 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 1 1 1 vertically.

%I A207689 #9 Jun 25 2018 07:53:21
%S A207689 9,81,100,256,576,1156,2500,5476,11664,24964,53824,115600,248004,
%T A207689 532900,1144900,2458624,5280804,11343424,24364096,52330756,112402404,
%U A207689 241429444,518563984,1113823876,2392383744,5138595856,11037183364,23706760900
%N A207689 Number of n X 4 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 1 1 1 vertically.
%C A207689 Column 4 of A207693.
%H A207689 R. H. Hardin, <a href="/A207689/b207689.txt">Table of n, a(n) for n = 1..210</a>
%F A207689 Empirical: a(n) = a(n-1) + a(n-2) + 3*a(n-3) + a(n-4) - a(n-5) - a(n-6) for n>8.
%F A207689 Empirical g.f.: x*(9 + 72*x + 10*x^2 + 48*x^3 - 32*x^4 - 48*x^5 - 10*x^6 + 17*x^7) / ((1 + x^2 - x^3)*(1 - x - 2*x^2 - x^3)). - _Colin Barker_, Jun 25 2018
%e A207689 Some solutions for n=4:
%e A207689 ..1..0..0..1....1..1..1..1....1..1..1..0....1..1..0..1....0..0..1..1
%e A207689 ..1..1..1..1....0..0..1..1....1..0..0..1....0..0..1..1....1..1..1..0
%e A207689 ..0..1..1..0....1..1..0..0....0..1..1..0....1..1..0..0....1..1..0..1
%e A207689 ..1..0..0..1....1..0..0..1....0..1..1..1....0..1..1..0....0..0..1..1
%Y A207689 Cf. A207693.
%K A207689 nonn
%O A207689 1,1
%A A207689 _R. H. Hardin_, Feb 19 2012