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A200662 Number of 0..2 arrays x(0..n-1) of n elements with each no smaller than the sum of its three previous neighbors modulo 3.

%I A200662 #7 Jun 02 2025 07:19:01
%S A200662 3,6,12,24,46,89,176,350,697,1391,2780,5555,11098,22170,44288,88472,
%T A200662 176729,353032,705224,1408771,2814203,5621746,11230193,22433834,
%U A200662 44814616,89523251,178834811,357246713,713648606,1425609609,2847847987,5688961529
%N A200662 Number of 0..2 arrays x(0..n-1) of n elements with each no smaller than the sum of its three previous neighbors modulo 3.
%C A200662 Column 2 of A200668
%H A200662 R. H. Hardin, <a href="/A200662/b200662.txt">Table of n, a(n) for n = 1..210</a>
%F A200662 Empirical: a(n) = 3*a(n-1) -3*a(n-2) +4*a(n-3) -6*a(n-4) +7*a(n-5) -9*a(n-6) +8*a(n-7) -6*a(n-8) +5*a(n-9) -4*a(n-10) +5*a(n-11) -5*a(n-12) +2*a(n-14) -3*a(n-15) +2*a(n-16) +a(n-17) -2*a(n-18) +5*a(n-19) -3*a(n-20) +a(n-21) -a(n-22) -a(n-24) +a(n-25) -a(n-26) +a(n-27)
%e A200662 Some solutions for n=6
%e A200662 ..0....2....0....0....1....0....0....2....0....1....1....0....1....1....1....1
%e A200662 ..1....2....0....0....1....0....1....2....1....2....1....0....2....1....2....2
%e A200662 ..2....2....2....1....2....0....2....2....1....1....2....2....0....2....0....0
%e A200662 ..0....2....2....2....1....2....0....0....2....1....2....2....2....1....1....2
%e A200662 ..1....2....2....0....1....2....1....1....2....2....2....1....1....1....0....1
%e A200662 ..2....0....1....2....2....2....1....0....2....2....0....2....0....1....2....2
%K A200662 nonn
%O A200662 1,1
%A A200662 _R. H. Hardin_ Nov 20 2011