A164423 Number of binary strings of length n with no substrings equal to 0000 0010 or 1100.

13, 21, 35, 59, 100, 171, 292, 497, 845, 1436, 2440, 4147, 7050, 11986, 20378, 34645, 58899, 100131, 170227, 289394, 491985, 836402, 1421931, 2417363, 4109652, 6986636, 11877667, 20192690, 34328690, 58360674, 99216379, 168673341

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

Formula

G.f.: -x^4*(13+8*x+x^2+3*x^3+6*x^4+12*x^5+8*x^6) / ( -1+x+x^2+x^6+x^7 ). - R. J. Mathar, Dec 01 2011

Crossrefs

Sequence in context: A164465 A164471 A164477 * A164422 A164500 A164430

Adjacent sequences: A164420 A164421 A164422 * A164424 A164425 A164426

Keyword

nonn,easy

Author

R. H. Hardin, Aug 14 2009

Status

approved