A164446 Number of binary strings of length n with no substrings equal to 0001 0010 or 0101.

13, 22, 37, 62, 103, 172, 286, 475, 789, 1311, 2177, 3615, 6003, 9968, 16551, 27482, 45632, 75768, 125806, 208890, 346843, 575901, 956231, 1587734, 2636286, 4377310, 7268120, 12068043, 20037872, 33271038, 55243489, 91726716, 152303748

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,-1,1,0,-1,1,-1).

Formula

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

Mathematica

LinearRecurrence[{2, -1, 1, 0, -1, 1, -1}, {13, 22, 37, 62, 103, 172, 286}, 40] (* Harvey P. Dale, Mar 12 2016 *)

Crossrefs

Sequence in context: A172187 A164412 A164472 * A164506 A164440 A164435

Adjacent sequences: A164443 A164444 A164445 * A164447 A164448 A164449

Keyword

nonn,easy

Author

R. H. Hardin, Aug 14 2009

Status

approved