A037641 Base 6 digits are, in order, the first n terms of the periodic sequence with initial period 2,3,1.

2, 15, 91, 548, 3291, 19747, 118484, 710907, 4265443, 25592660, 153555963, 921335779, 5528014676, 33168088059, 199008528355, 1194051170132, 7164307020795, 42985842124771, 257915052748628, 1547490316491771

Offset

1,1

Links

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

Index entries for linear recurrences with constant coefficients, signature (6,0,1,-6).

Formula

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

Mathematica

Table[FromDigits[PadRight[{}, n, {2, 3, 1}], 6], {n, 20}] (* or *) LinearRecurrence[{6, 0, 1, -6}, {2, 15, 91, 548}, 20] (* Harvey P. Dale, Jul 06 2021 *)

Prog

(PARI) a(n)=([0, 1, 0, 0; 0, 0, 1, 0; 0, 0, 0, 1; -6, 1, 0, 6]^(n-1)*[2; 15; 91; 548])[1, 1] \\ Charles R Greathouse IV, Jun 02 2026

Crossrefs

Sequence in context: A037627 A192369 A037753 * A361303 A288952 A356554

Adjacent sequences: A037638 A037639 A037640 * A037642 A037643 A037644

Keyword

nonn,base,easy,changed

Author

Clark Kimberling

Status

approved