%I #4 May 17 2012 14:33:29
%S 146861788,523487828,1908601444,7023308036,25966120647,96239314549,
%T 357117150362,1325550644016,4918335298665,18232047941771,
%U 67489103954016,249349516426188,919083218908202,3377977784235134,12373106402582424
%N Number of 0..3 arrays of length n+13 with sum no more than 21 in any length 14 subsequence (=50% duty cycle)
%C Column 7 of A212471
%H R. H. Hardin, <a href="/A212470/b212470.txt">Table of n, a(n) for n = 1..36</a>
%e Some solutions for n=3
%e ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
%e ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
%e ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
%e ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
%e ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
%e ..2....2....0....0....2....0....0....0....2....0....2....2....0....0....0....2
%e ..0....0....2....2....0....0....2....2....0....2....0....0....2....2....0....0
%e ..2....2....0....2....0....2....2....2....0....2....2....0....2....2....0....2
%e ..2....0....2....2....0....0....0....2....2....0....0....2....0....2....0....2
%e ..2....0....0....0....0....0....2....2....0....0....2....2....2....0....0....0
%e ..2....3....3....2....0....2....1....2....0....3....1....1....1....3....2....1
%e ..1....1....0....2....1....3....1....2....0....3....0....3....3....3....1....3
%e ..0....3....2....2....3....1....0....0....1....3....3....0....2....3....2....2
%e ..3....0....3....0....3....2....3....1....0....1....1....3....1....3....0....2
%e ..1....2....0....1....1....2....0....0....0....1....2....2....1....2....2....2
%e ..3....0....2....3....0....1....1....2....2....0....1....1....0....0....2....0
%K nonn
%O 1,1
%A _R. H. Hardin_ May 17 2012