A164508 Number of binary strings of length n with no substrings equal to 0101, 0110, or 1001.

1, 2, 4, 8, 13, 20, 33, 56, 93, 152, 250, 414, 685, 1130, 1864, 3078, 5084, 8394, 13857, 22878, 37775, 62370, 102975, 170016, 280708, 463468, 765213, 1263410, 2085966, 3444058, 5686348, 9388500, 15500977, 25593048, 42255665, 69766644, 115188925, 190183848

Offset

0,2

Links

Alois P. Heinz, Table of n, a(n) for n = 0..2000 (first 500 terms from R. H. Hardin)

Index entries for linear recurrences with constant coefficients, signature (2,-1,0,2,-2,1).

Formula

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

Crossrefs

Sequence in context: A164487 A130840 A115266 * A308094 A292774 A026039

Adjacent sequences: A164505 A164506 A164507 * A164509 A164510 A164511

Keyword

nonn,easy

Author

R. H. Hardin, Aug 14 2009

Extensions

Edited by Alois P. Heinz, Feb 14 2018

Status

approved