A164436 Number of binary strings of length n with no substrings equal to 0000 0101 or 1110.

13, 21, 33, 52, 81, 126, 196, 304, 471, 730, 1131, 1751, 2711, 4198, 6499, 10060, 15574, 24110, 37321, 57772, 89433, 138441, 214301, 331736, 513525, 794922, 1230520, 1904828, 2948635, 4564414, 7065623, 10937451, 16930931, 26208714, 40570567

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 (1,0,2,0,-1,-1).

Formula

G.f.: -x^4*(-13-8*x-12*x^2+7*x^3+13*x^4+8*x^5) / ( (x-1)*(x^5+2*x^4+2*x^3-1) ). - R. J. Mathar, Jan 19 2011

Mathematica

LinearRecurrence[{1, 0, 2, 0, -1, -1}, {13, 21, 33, 52, 81, 126}, 40] (* Harvey P. Dale, Sep 01 2016 *)

Crossrefs

Sequence in context: A164499 A164442 A164488 * A164498 A164485 A164447

Adjacent sequences: A164433 A164434 A164435 * A164437 A164438 A164439

Keyword

nonn,easy

Author

R. H. Hardin, Aug 14 2009

Status

approved