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A200661 Number of 0..1 arrays x(0..n-1) of n elements with each no smaller than the sum of its three previous neighbors modulo 2.

%I A200661 #9 May 21 2018 15:19:05
%S A200661 2,3,5,8,12,17,25,36,51,72,102,144,202,284,399,560,785,1101,1544,2164,
%T A200661 3033,4251,5958,8349,11700,16396,22976,32196,45116,63221,88590,124139,
%U A200661 173953,243756,341568,478629,670689,939816,1316935,1845380,2585874
%N A200661 Number of 0..1 arrays x(0..n-1) of n elements with each no smaller than the sum of its three previous neighbors modulo 2.
%C A200661 Column 1 of A200668.
%H A200661 R. H. Hardin, <a href="/A200661/b200661.txt">Table of n, a(n) for n = 1..210</a>
%F A200661 Empirical: a(n)=a(n-1)+a(n-2)-a(n-5)-a(n-6)+a(n-7).
%F A200661 Empirical g.f.: x*(1 + x^2)*(2 + x - 2*x^2 - x^3 + x^4) / ((1 - x)*(1 - x^2 - x^3 - x^4 + x^6)). - _Colin Barker_, May 21 2018
%e A200661 Some solutions for n=6:
%e A200661 ..0....0....0....0....0....1....0....0....0....1....1....1....0....0....1....0
%e A200661 ..0....0....0....0....0....1....1....1....1....1....1....1....0....1....1....0
%e A200661 ..0....1....0....0....1....0....1....1....1....0....0....0....0....1....1....1
%e A200661 ..1....1....1....0....1....1....0....0....0....0....1....1....0....1....1....1
%e A200661 ..1....0....1....0....1....1....0....1....1....1....0....1....0....1....1....0
%e A200661 ..0....1....1....1....1....1....1....0....1....1....1....0....0....1....1....0
%Y A200661 Cf. A200668.
%K A200661 nonn
%O A200661 1,1
%A A200661 _R. H. Hardin_, Nov 20 2011