A164431 Number of binary strings of length n with no substrings equal to 0000 0011 or 1101

13, 21, 34, 54, 86, 139, 225, 364, 590, 956, 1547, 2503, 4050, 6552, 10600, 17151, 27751, 44902, 72654, 117558, 190213, 307771, 497984, 805754, 1303736, 2109489, 3413225, 5522714, 8935940, 14458656, 23394597, 37853253, 61247850, 99101102

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,-1,0,1).

Formula

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

Mathematica

LinearRecurrence[{2, -1, 1, -1, 0, 1}, {13, 21, 34, 54, 86, 139}, 40] (* Harvey P. Dale, May 19 2016 *)

Crossrefs

Sequence in context: A164481 A164433 A164479 * A164497 A164503 A067516

Adjacent sequences: A164428 A164429 A164430 * A164432 A164433 A164434

Keyword

nonn

Author

R. H. Hardin Aug 14 2009

Status

approved