A037582 Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 1,3.

1, 13, 131, 1313, 13131, 131313, 1313131, 13131313, 131313131, 1313131313, 13131313131, 131313131313, 1313131313131, 13131313131313, 131313131313131, 1313131313131313, 13131313131313131, 131313131313131313, 1313131313131313131, 13131313131313131313

Offset: 1

Author

Clark Kimberling

Keywords

• nonn
• base
• easy

Links

• Index entries for linear recurrences with constant coefficients, signature (10,1,-10).

Crossrefs

Cf. A156641 (even bisection).

Programs

Mathematica

Table[FromDigits[PadRight[{},n,{1,3}]],{n,20}] (* Harvey P. Dale, Feb 11 2015 *)

PARI

Vec(x*(1+3*x)/((x-1)*(10*x-1)*(1+x)) + O(x^25)) \\ Jinyuan Wang, Apr 14 2020

Formula

G.f.: x*(1+3*x) / ( (x-1)*(10*x-1)*(1+x) ). - R. J. Mathar, Aug 12 2013

Extensions

More terms from Harvey P. Dale, Feb 11 2015