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, 11011011011011011, 110110110110110110, 1101101101101101101, 11011011011011011011

Offset

1,2

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).

Formula

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

a(n) = floor(110*10^n/999). - Christian Krause, May 21 2026

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 *)

Crossrefs

Sequence in context: A281281 A281636 A281088 * A065829 A261299 A081933

Adjacent sequences: A033134 A033135 A033136 * A033138 A033139 A033140

Keyword

nonn,base,easy

Author

Clark Kimberling

Status

approved