# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a212723 Showing 1-1 of 1 %I A212723 #5 May 25 2012 20:39:53 %S A212723 31,67,148,322,677,1439,3086,6625,14161,30244,64669,138374,295991, %T A212723 632942,1353515,2894804,6191317,13241220,28318162,60563023,129525173, %U A212723 277012820,592439104,1267031754,2709766972,5795308821,12394271806,26507289874 %N A212723 Number of 0..2 arrays of length n+3 with sum less than 4 in any length 4 subsequence (=less than 50% duty cycle) %C A212723 Column 2 of A212729 %H A212723 R. H. Hardin, Table of n, a(n) for n = 1..210 %F A212723 Empirical: a(n) = a(n-1) +a(n-2) +a(n-3) +5*a(n-4) +a(n-5) -2*a(n-6) -3*a(n-7) -6*a(n-8) -2*a(n-9) +a(n-10) +3*a(n-11) +4*a(n-12) -a(n-15) -a(n-16) %e A212723 Some solutions for n=3 %e A212723 ..1....0....1....1....0....1....0....0....2....1....2....2....0....1....2....1 %e A212723 ..0....0....1....0....1....1....1....1....0....0....1....1....1....0....0....0 %e A212723 ..1....0....0....0....1....1....0....0....1....0....0....0....0....0....0....1 %e A212723 ..1....1....0....0....0....0....0....2....0....1....0....0....0....0....1....0 %e A212723 ..1....0....1....2....0....1....0....0....0....0....1....0....0....1....0....0 %e A212723 ..0....2....2....0....0....1....0....0....1....0....1....2....1....2....2....1 %K A212723 nonn %O A212723 1,1 %A A212723 _R. H. Hardin_ May 25 2012 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE