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A164505
Number of binary strings of length n with no substrings equal to 0011 0101 or 1100.
1
13, 20, 31, 48, 74, 114, 175, 268, 410, 626, 954, 1452, 2207, 3350, 5079, 7692, 11637, 17588, 26558, 40068, 60401, 90982, 136946, 205988, 309634, 465140, 698329, 1047828, 1571393, 2355348, 3528667, 5283976, 7908866, 11832566, 17695491
OFFSET
4,1
FORMULA
G.f.: -x^4*(-13+6*x-4*x^2+20*x^3+5*x^4+8*x^5) / ( (x^3+x-1)^2 ). - R. J. Mathar, Jan 19 2011
CROSSREFS
Sequence in context: A164489 A164464 A164467 * A164484 A164502 A164474
KEYWORD
nonn,easy
AUTHOR
R. H. Hardin, Aug 14 2009
STATUS
approved