A164503 Number of binary strings of length n with no substrings equal to 0011 0101 or 0110.

13, 21, 34, 55, 87, 136, 211, 326, 501, 766, 1166, 1769, 2676, 4037, 6075, 9122, 13671, 20453, 30551, 45569, 67881, 100998, 150109, 222879, 330625, 490048, 725783, 1074153, 1588694, 2348284, 3469100, 5122202, 7559387, 11151195, 16442768

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,-1,0,-1).

Formula

G.f.: -x^4*(-13+5*x-5*x^2+5*x^3+10*x^4+4*x^5+8*x^6) / ( (x^3+x-1)*(x^4+x-1) ). - R. J. Mathar, Jan 19 2011

Mathematica

LinearRecurrence[{2, -1, 1, 0, -1, 0, -1}, {13, 21, 34, 55, 87, 136, 211}, 40] (* Harvey P. Dale, Sep 28 2017 *)

Crossrefs

Sequence in context: A164433 A164479 A164497 * A164449 A164439 A164492

Adjacent sequences: A164500 A164501 A164502 * A164504 A164505 A164506

Keyword

nonn,easy

Author

R. H. Hardin, Aug 14 2009

Status

approved