A249284 - OEIS

%I #5 Oct 24 2014 08:26:53

%S 66,168,428,1094,2792,7132,18232,46616,119176,304696,779066,1992002,

%T 5093330,13023126,33299000,85142802,217703012,556648464,1423304428,

%U 3639273226,9305324178,23792953554,60836640416,155554327024,397739724496

%N Number of length n+3 0..2 arrays with no four consecutive terms having the sum of any three elements equal to three times the fourth

%C Column 2 of A249290

%H R. H. Hardin, <a href="/A249284/b249284.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) +2*a(n-2) +3*a(n-3) +7*a(n-4) +a(n-5) -6*a(n-6) -12*a(n-7) -14*a(n-8) -14*a(n-9) -7*a(n-10) +3*a(n-11) +2*a(n-12)

%e Some solutions for n=9

%e ..1....0....2....2....1....1....0....1....1....1....0....1....1....2....2....1

%e ..1....0....1....0....0....1....1....0....1....0....0....1....1....0....1....0

%e ..0....1....0....0....2....0....2....2....2....2....0....1....2....0....0....2

%e ..1....0....0....0....2....1....0....2....2....0....2....2....1....0....0....2

%e ..0....1....2....1....0....0....0....0....1....2....2....2....2....1....1....2

%e ..2....0....2....0....0....0....0....1....2....1....0....0....2....0....1....0

%e ..0....1....2....0....0....1....2....0....2....2....2....2....1....0....0....0

%e ..2....1....0....1....1....1....0....1....2....1....0....2....0....1....0....2

%e ..0....0....0....1....2....0....2....0....0....2....2....1....0....0....2....2

%e ..2....0....2....1....2....1....1....0....0....1....1....2....0....2....1....2

%e ..2....0....2....2....1....0....2....0....1....2....2....0....2....0....2....1

%e ..2....2....1....2....2....0....2....1....2....0....1....0....2....0....2....0

%K nonn

%O 1,1

%A _R. H. Hardin_, Oct 24 2014