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A164403
Number of binary strings of length n with no substrings equal to 0010 or 1001
1
14, 25, 45, 80, 143, 255, 455, 812, 1449, 2586, 4615, 8236, 14698, 26230, 46810, 83537, 149080, 266048, 474789, 847308, 1512105, 2698501, 4815742, 8594168, 15337143, 27370649, 48845631, 87169861, 155563241, 277617994, 495436776, 884155942
OFFSET
4,1
FORMULA
G.f.: x^4*(14-3*x-5*x^2+4*x^3+8*x^4)/(1-2*x+x^3-x^5). - R. J. Mathar, Nov 30 2011
MATHEMATICA
LinearRecurrence[{2, 0, -1, 0, 1}, {14, 25, 45, 80, 143}, 50] (* G. C. Greubel, Sep 19 2017 *)
PROG
(PARI) x='x+O('x^50); Vec(x^4*(14-3*x-5*x^2+4*x^3+8*x^4)/(1-2*x+x^3-x^5)) \\ G. C. Greubel, Sep 19 2017
CROSSREFS
Sequence in context: A020227 A032608 A341171 * A164398 A174519 A079505
KEYWORD
nonn
AUTHOR
R. H. Hardin, Aug 14 2009
STATUS
approved