A164450 Number of binary strings of length n with no substrings equal to 0001 0010 or 1011.

13, 21, 33, 51, 78, 119, 181, 275, 417, 632, 957, 1449, 2193, 3319, 5022, 7599, 11497, 17395, 26317, 39816, 60237, 91133, 137873, 208587, 315566, 477415, 722269, 1092707, 1653129, 2500984, 3783677, 5724241, 8660065, 13101615, 19821118

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

Formula

G.f.: -x^4*(-13+5*x+9*x^2-11*x^3+8*x^4) / ( (x-1)*(x^4-x^3+x^2+x-1) ). - R. J. Mathar, Jan 19 2011

Crossrefs

Sequence in context: A164460 A164448 A164424 * A164461 A164499 A164442

Adjacent sequences: A164447 A164448 A164449 * A164451 A164452 A164453

Keyword

nonn,easy

Author

R. H. Hardin, Aug 14 2009

Status

approved