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A207094 Number of 0..2 arrays x(0..n-1) of n elements with each no smaller than the sum of its two previous neighbors modulo 3.

%I A207094 #9 Jun 18 2018 14:17:37
%S A207094 3,6,12,26,55,115,239,498,1038,2162,4502,9375,19523,40655,84659,
%T A207094 176292,367107,764456,1591886,3314907,6902887,14374415,29932954,
%U A207094 62331700,129798109,270288619,562842849,1172051097,2440652442,5082358916
%N A207094 Number of 0..2 arrays x(0..n-1) of n elements with each no smaller than the sum of its two previous neighbors modulo 3.
%C A207094 Column 2 of A207100.
%H A207094 R. H. Hardin, <a href="/A207094/b207094.txt">Table of n, a(n) for n = 1..210</a>
%F A207094 Empirical: a(n) = 2*a(n-1) + a(n-4) - a(n-6) - a(n-9).
%F A207094 Empirical g.f.: x*(3 + 2*x^3 - x^5 - x^8) / ((1 - x)*(1 - x - x^2 - x^3 - 2*x^4 - 2*x^5 - x^6 - x^7 - x^8)). - _Colin Barker_, Jun 18 2018
%e A207094 Some solutions for n=5:
%e A207094 ..1....0....1....0....0....0....0....0....1....0....1....1....0....0....0....0
%e A207094 ..2....1....2....1....1....0....0....2....1....0....2....2....1....1....0....0
%e A207094 ..2....1....1....1....2....0....2....2....2....0....1....2....2....2....0....0
%e A207094 ..1....2....1....2....2....0....2....1....2....1....0....1....1....1....0....0
%e A207094 ..2....2....2....0....1....1....2....2....2....2....1....0....2....0....0....2
%Y A207094 Cf. A207100.
%K A207094 nonn
%O A207094 1,1
%A A207094 _R. H. Hardin_, Feb 15 2012