%I
%S 1,19,136,714,3354,14946,64664,274676,1152494,4793874,19813536,
%T 81495084,333932596,1364199604,5559496912,22610923448,91805888342,
%U 372224952818,1507347830672,6097720950428,24644919356012,99527343620348
%N Number of binary arrays of length 2*n+4 with fewer than n ones in any length 2n subsequence (=less than 50% duty cycle)
%C Row 5 of A213118
%H R. H. Hardin, <a href="/A213122/b213122.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: 3*n*(77*n237)*a(n) = 2*(924*n^23545*n+2311)*a(n1)  8*(462*n^22131*n+2347)*a(n2)  128*(2*n9)*a(n3).  _Vaclav Kotesovec_, Oct 19 2012
%e Some solutions for n=3
%e ..0....0....0....0....0....0....0....0....1....1....1....0....0....0....1....1
%e ..1....0....1....0....0....0....1....0....0....0....0....0....0....1....0....0
%e ..0....0....0....0....0....0....0....1....0....1....0....0....1....0....1....0
%e ..0....0....0....0....0....0....0....0....1....0....0....1....0....0....0....0
%e ..1....0....0....0....1....0....1....0....0....0....0....0....0....0....0....0
%e ..0....1....0....0....1....0....0....1....0....0....0....0....0....0....0....0
%e ..0....0....0....1....0....1....0....0....0....1....0....0....0....1....0....0
%e ..1....0....0....1....0....0....0....0....0....0....1....1....1....0....1....1
%e ..0....0....1....0....0....1....0....1....0....1....0....0....0....0....0....0
%e ..0....1....0....0....0....0....1....0....1....0....1....0....1....1....0....0
%K nonn
%O 1,2
%A _R. H. Hardin_ Jun 05 2012
