A037757 Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 2,3,1,0.

2, 23, 231, 2310, 23102, 231023, 2310231, 23102310, 231023102, 2310231023, 23102310231, 231023102310, 2310231023102, 23102310231023, 231023102310231, 2310231023102310, 23102310231023102, 231023102310231023, 2310231023102310231, 23102310231023102310

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..200

Index entries for linear recurrences with constant coefficients, signature (11,-11,11,-10)

Formula

G.f.: (2+x)*x / ((x-1)*(10*x-1)*(x^2+1)). - R. J. Mathar, Nov 21 2011

Mathematica

CoefficientList[Series[(2 + x) / ((x - 1) (10 x - 1) (x^2 + 1)), {x, 0, 40}], x] (* Vincenzo Librandi, Feb 16 2018 *)
Table[FromDigits[PadRight[{}, n, {2, 3, 1, 0}]], {n, 20}] (* Harvey P. Dale, Oct 21 2018 *)

Prog

(Magma) I:=[2, 23, 231, 2310]; [n le 4 select I[n] else 11*Self(n-1)-11*Self(n-2)+11*Self(n-3)-10*Self(n-4): n in [1..30]]; // Vincenzo Librandi, Feb 16 2018

Crossrefs

Sequence in context: A037750 A037631 A026075 * A037645 A100893 A356557

Adjacent sequences: A037754 A037755 A037756 * A037758 A037759 A037760

Keyword

nonn,base

Author

Clark Kimberling

Status

approved