A037785 Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 3,1,2,0.

3, 31, 312, 3120, 31203, 312031, 3120312, 31203120, 312031203, 3120312031, 31203120312, 312031203120, 3120312031203, 31203120312031, 312031203120312, 3120312031203120

Offset

1,1

Links

Table of n, a(n) for n=1..16.

Index entries for linear recurrences with constant coefficients, signature (10,0,0,1,-10).

Formula

G.f.: x*(3+x+2*x^2) / ( (x-1)*(10*x-1)*(1+x)*(x^2+1) ). - R. J. Mathar, Aug 04 2013

Mathematica

Table[FromDigits[PadRight[{}, n, {3, 1, 2, 0}]], {n, 30}] (* Harvey P. Dale, Mar 15 2020 *)

Prog

(PARI) Vec(x*(3+x+2*x^2)/((x-1)*(10*x-1)*(1+x)*(x^2+1)) + O(x^25)) \\ Jinyuan Wang, Apr 14 2020

Crossrefs

Sequence in context: A108430 A113075 A111137 * A037589 A247351 A089289

Adjacent sequences: A037782 A037783 A037784 * A037786 A037787 A037788

Keyword

nonn,base,easy

Author

Clark Kimberling

Status

approved