A037491 Base 6 digits are, in order, the first n terms of the periodic sequence with initial period 2,1.

2, 13, 80, 481, 2888, 17329, 103976, 623857, 3743144, 22458865, 134753192, 808519153, 4851114920, 29106689521, 174640137128, 1047840822769, 6287044936616, 37722269619697, 226333617718184, 1358001706309105

Offset

1,1

Links

Table of n, a(n) for n=1..20.

Index entries for linear recurrences with constant coefficients, signature (6,1,-6).

Formula

a(n) = 6a(n-1) + a(n-2) - 6a(n-3).

G.f.: x*(2+x) / ( (x-1)*(6*x-1)*(1+x) ). - R. J. Mathar, Nov 21 2011

Mathematica

Module[{nn=20, d}, d=PadRight[{}, nn, {2, 1}]; Table[FromDigits[Take[d, n], 6], {n, nn}]] (* or *) LinearRecurrence[{6, 1, -6}, {2, 13, 80}, 20] (* Harvey P. Dale, Feb 26 2015 *)

Crossrefs

Sequence in context: A037555 A135167 A271475 * A037571 A179237 A216316

Adjacent sequences: A037488 A037489 A037490 * A037492 A037493 A037494

Keyword

nonn,base,easy

Author

Clark Kimberling

Extensions

An incorrect recurrence was deleted by N. J. A. Sloane, Sep 13 2009

Status

approved