A037556 Base 7 digits are, in order, the first n terms of the periodic sequence with initial period 2,1,1.

2, 15, 106, 744, 5209, 36464, 255250, 1786751, 12507258, 87550808, 612855657, 4289989600, 30029927202, 210209490415, 1471466432906, 10300265030344, 72101855212409, 504712986486864, 3532990905408050

Offset

1,1

Links

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

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

Formula

G.f.: x*(2+x+x^2) / ( (x-1)*(7*x-1)*(1+x+x^2) ). - R. J. Mathar, Apr 30 2015

Mathematica

nn=30; With[{c=PadRight[{}, nn, {2, 1, 1}]}, Table[FromDigits[Take[c, n], 7], {n, nn}]] (* Harvey P. Dale, May 05 2012 *)

Crossrefs

Sequence in context: A037524 A037733 A308938 * A037492 A037572 A218686

Adjacent sequences: A037553 A037554 A037555 * A037557 A037558 A037559

Keyword

nonn,base,easy

Author

Clark Kimberling

Status

approved