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 A213122 Number of binary arrays of length 2*n+4 with fewer than n ones in any length 2n subsequence (=less than 50% duty cycle) 1

%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*n-237)*a(n) = 2*(924*n^2-3545*n+2311)*a(n-1) - 8*(462*n^2-2131*n+2347)*a(n-2) - 128*(2*n-9)*a(n-3). - _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

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Last modified October 15 07:46 EDT 2019. Contains 328026 sequences. (Running on oeis4.)