A212476 - OEIS

%I #4 May 17 2012 14:39:52

%S 707,16649,321320,5622580,95010466,1578372444,25966120647,

%T 424537002094,6911873593516,112193588288892,1817051683302947,

%U 29377851622547612,474335448720482746,7650319463541214660,123278749437509026298

%N Number of 0..3 arrays of length 2*n+4 with sum no more than 3*n in any length 2n subsequence (=50% duty cycle)

%C Row 5 of A212471

%H R. H. Hardin, <a href="/A212476/b212476.txt">Table of n, a(n) for n = 1..210</a>

%e Some solutions for n=3

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

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

%e ..0....3....1....3....3....2....3....3....2....2....3....0....1....1....0....2

%e ..3....3....3....2....1....3....1....0....0....2....2....2....2....1....3....0

%e ..1....0....0....0....0....0....2....1....0....2....0....3....2....0....1....0

%e ..0....0....0....0....0....0....0....1....1....1....0....0....3....0....1....1

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

%e ..0....3....3....2....1....2....3....3....0....0....2....0....1....2....3....3

%e ..0....2....1....2....1....3....1....2....0....0....2....3....1....2....0....3

%e ..1....1....1....3....3....0....3....2....1....0....1....3....1....1....1....0

%K nonn

%O 1,1

%A _R. H. Hardin_ May 17 2012