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A037768
Base 7 digits are, in order, the first n terms of the periodic sequence with initial period 3,0,2,1.
1
3, 21, 149, 1044, 7311, 51177, 358241, 2507688, 17553819, 122876733, 860137133, 6020959932, 42146719527, 295027036689, 2065189256825, 14456324797776, 101194273584435, 708359915091045, 4958519405637317
OFFSET
1,1
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
KEYWORD
nonn,base,easy
STATUS
approved