A164449 Number of binary strings of length n with no substrings equal to 0001 0010 or 1010.

13, 21, 34, 56, 91, 147, 238, 386, 625, 1011, 1636, 2648, 4285, 6933, 11218, 18152, 29371, 47523, 76894, 124418, 201313, 325731, 527044, 852776, 1379821, 2232597, 3612418, 5845016, 9457435, 15302451, 24759886, 40062338, 64822225, 104884563

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).

Formula

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

Crossrefs

Sequence in context: A164479 A164497 A164503 * A164439 A164492 A164451

Adjacent sequences: A164446 A164447 A164448 * A164450 A164451 A164452

Keyword

nonn,easy

Author

R. H. Hardin, Aug 14 2009

Status

approved