A037768 Base 7 digits are, in order, the first n terms of the periodic sequence with initial period 3,0,2,1.

3, 21, 149, 1044, 7311, 51177, 358241, 2507688, 17553819, 122876733, 860137133, 6020959932, 42146719527, 295027036689, 2065189256825, 14456324797776, 101194273584435, 708359915091045, 4958519405637317

Offset

1,1

Links

Table of n, a(n) for n=1..19.

Index entries for linear recurrences with constant coefficients, signature (7,0,0,1,-7).

Formula

a(n) = 7a(n-1) + a(n-4) - 7a(n-5).

G.f.: x*(3+2*x^2+x^3) / ( (x-1)*(7*x-1)*(1+x)*(x^2+1) ). - R. J. Mathar, May 02 2015

Mathematica

nn=20; With[{c=PadRight[{}, nn, {3, 0, 2, 1}]}, Table[FromDigits[Take[c, n], 7], {n, nn}]] (* or *) LinearRecurrence[{7, 0, 0, 1, -7}, {3, 21, 149, 1044, 7311}, 20] (* Harvey P. Dale, Jul 10 2012 *)

Crossrefs

Sequence in context: A357652 A037761 A037649 * A037656 A074577 A007566

Adjacent sequences: A037765 A037766 A037767 * A037769 A037770 A037771

Keyword

nonn,base,easy

Author

Clark Kimberling

Status

approved