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A164409
Number of binary strings of length n with no substrings equal to 0000 0001 or 0100.
1
13, 22, 39, 69, 121, 212, 372, 653, 1146, 2011, 3529, 6193, 10868, 19072, 33469, 58734, 103071, 180877, 317417, 557028, 977516, 1715421, 3010354, 5282803, 9270673, 16268897, 28549924, 50101624, 87922221, 154292742, 270764887, 475159253
OFFSET
4,1
FORMULA
G.f.: x^4*(13-4*x+8*x^2)/(1-2*x+x^2-x^3). - R. J. Mathar, Nov 30 2011
MATHEMATICA
LinearRecurrence[{2, -1, 1}, {13, 22, 39}, 50] (* G. C. Greubel, Sep 19 2017 *)
PROG
(PARI) my(x='x+O('x^50)); Vec(x^4*(13-4*x+8*x^2)/(1-2*x+x^2-x^3)) \\ G. C. Greubel, Sep 19 2017
CROSSREFS
Sequence in context: A164445 A164418 A301788 * A301962 A298235 A111676
KEYWORD
nonn,easy
AUTHOR
R. H. Hardin, Aug 14 2009
STATUS
approved