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A164451 Number of binary strings of length n with no substrings equal to 0001 0010 or 1100 1
13, 21, 34, 56, 93, 156, 261, 437, 731, 1223, 2046, 3424, 5730, 9590, 16050, 26862, 44957, 75242, 125928, 210759, 352736, 590356, 988048, 1653645, 2767620, 4632023, 7752378, 12974756, 21715181, 36343581, 60826381, 101801984, 170380742 (list; graph; refs; listen; history; text; internal format)
OFFSET

4,1

LINKS

R. H. Hardin, Table of n, a(n) for n=4..500

Index entries for linear recurrences with constant coefficients, signature (2,0,-1,0,0,1,-1).

FORMULA

G.f. -x^4*(-13+5*x+8*x^2-x^3-2*x^4-4*x^5+8*x^6) / ( (x-1)*(1+x)*(x^5-x^4+x^3-x^2+2*x-1) ). - R. J. Mathar, Jan 19 2011

MATHEMATICA

LinearRecurrence[{2, 0, -1, 0, 0, 1, -1}, {13, 21, 34, 56, 93, 156, 261}, 40] (* Harvey P. Dale, Dec 30 2017 *)

CROSSREFS

Sequence in context: A164449 A164439 A164492 * A164432 A034292 A163113

Adjacent sequences:  A164448 A164449 A164450 * A164452 A164453 A164454

KEYWORD

nonn

AUTHOR

R. H. Hardin Aug 14 2009

STATUS

approved

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Last modified September 20 16:50 EDT 2021. Contains 347586 sequences. (Running on oeis4.)