A164433 Number of binary strings of length n with no substrings equal to 0000 0101 or 0111.

13, 21, 34, 54, 84, 131, 205, 318, 492, 764, 1185, 1833, 2838, 4398, 6808, 10535, 16313, 25258, 39092, 60512, 93685, 145021, 224474, 347494, 537932, 832683, 1288965, 1995334, 3088732, 4781236, 7401289, 11457105, 17735278, 27453790, 42498032

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-13*x^2+6*x^3+12*x^4+8*x^5) / ( (x-1)*(x^5+2*x^4+2*x^3-1) ). - R. J. Mathar, Jan 19 2011

Crossrefs

Sequence in context: A164426 A164473 A164481 * A164479 A164497 A164503

Adjacent sequences: A164430 A164431 A164432 * A164434 A164435 A164436

Keyword

nonn,easy

Author

R. H. Hardin, Aug 14 2009

Status

approved