A164442 Number of binary strings of length n with no substrings equal to 0000 0111 or 1001.

13, 21, 33, 51, 79, 122, 188, 289, 444, 682, 1047, 1607, 2466, 3784, 5806, 8908, 13667, 20968, 32169, 49353, 75716, 116161, 178210, 273403, 419444, 643494, 987222, 1514555, 2323567, 3564719, 5468842, 8390067, 12871687, 19747199, 30295319

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

Formula

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

Crossrefs

Sequence in context: A164450 A164461 A164499 * A164488 A164436 A164498

Adjacent sequences: A164439 A164440 A164441 * A164443 A164444 A164445

Keyword

nonn,easy

Author

R. H. Hardin, Aug 14 2009

Status

approved