This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A037589 Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 3,1. 0

%I

%S 3,31,313,3131,31313,313131,3131313,31313131,313131313,3131313131,

%T 31313131313,313131313131,3131313131313,31313131313131,

%U 313131313131313,3131313131313131

%N Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 3,1.

%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (10,1,-10).

%F G.f.: x*(3+x)/(1-10*x-x^2+10*x^3). - _Jaume Oliver Lafont_, Mar 24 2009

%F a(n)=10*a(n-1)+2-(-1)^n, with a(0)=0. Closed form: a(n)=-(2/9)-(1/11)*(-1)^n+(31/99)*10^n, with n>=1. - _Paolo P. Lava_, Mar 31 2009

%t Table[FromDigits[PadRight[{},n,{3,1}]],{n,20}] (* _Harvey P. Dale_, Oct 19 2016 *)

%K nonn,base,easy

%O 1,1

%A _Clark Kimberling_

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 18 02:23 EDT 2019. Contains 328135 sequences. (Running on oeis4.)