A033137 Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 1,1,0.

1, 11, 110, 1101, 11011, 110110, 1101101, 11011011, 110110110, 1101101101, 11011011011, 110110110110, 1101101101101, 11011011011011, 110110110110110, 1101101101101101

Offset: 1

Author

Clark Kimberling

Keywords

• nonn
• base
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000
• Index entries for linear recurrences with constant coefficients, signature (10,0,1,-10).

Programs

Mathematica

Table[FromDigits[PadRight[{},n,{1,1,0}]],{n,20}] (* Harvey P. Dale, Aug 13 2014 *)
CoefficientList[Series[(1 + x)/((x - 1) (10 x - 1) (1 + x + x^2)), {x, 0, 20}], x] (* Vincenzo Librandi, Aug 14 2014 *)

Formula

G.f.: x*(1+x) / ( (x-1)*(10*x-1)*(1+x+x^2) ). - R. J. Mathar, Jan 08 2011