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%I #8 Mar 05 2018 09:28:04
%S 6,36,60,144,312,612,1250,2516,4968,9796,19256,37740,73704,143810,
%T 280340,545664,1061676,2064584,4012968,7798252,15150258,29428972,
%U 57157720,111001924,215555184,418562876,812728688,1578038530,3063930012
%N Number of n X 3 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 1 1 1 vertically.
%C Column 3 of A207589.
%H R. H. Hardin, <a href="/A207584/b207584.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = a(n-1) + a(n-2) + 4*a(n-3) - 2*a(n-4) - a(n-5) - 8*a(n-6) + a(n-7) - 3*a(n-8) + 3*a(n-9) -2 *a(n-10) - a(n-12) for n>14.
%F Empirical g.f.: 2*x*(3 + 15*x + 9*x^2 + 12*x^3 - 12*x^4 - 3*x^5 - 23*x^6 + 18*x^7 - 8*x^8 + 15*x^9 - 12*x^10 + 3*x^11 - 3*x^12 + 2*x^13) / ((1 - x - x^3)*(1 - x^2 - 4*x^3 - 2*x^4 - 2*x^5 + 2*x^6 - x^7 - x^9)). - _Colin Barker_, Mar 05 2018
%e Some solutions for n=4:
%e ..1..1..1....0..1..1....0..1..1....0..1..0....1..1..1....1..1..0....1..0..0
%e ..0..1..0....1..0..1....1..0..1....1..0..0....1..0..0....0..1..0....1..1..1
%e ..1..0..0....0..1..0....1..1..0....0..1..0....0..1..1....1..0..0....0..1..1
%e ..0..1..0....1..1..1....0..1..1....1..0..0....1..1..0....0..1..0....1..0..0
%Y Cf. A207589.
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 19 2012
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