OFFSET
0,3
COMMENTS
Equivalently: n^(6*m+7) mod 21. - G. C. Greubel, Jun 04 2016
LINKS
Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1).
FORMULA
a(n) = a(n-21). - R. J. Mathar, Sep 30 2013
MATHEMATICA
PowerMod[Range[0, 90], 7, 21] (* or *) PadRight[{}, 90, Range[0, 20]] (* Harvey P. Dale, Apr 21 2012 *)
PROG
(Sage) [power_mod(n, 7, 21)for n in range(0, 85)] #
(PARI) a(n)=n^7%21 \\ Charles R Greathouse IV, Apr 06 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Zerinvary Lajos, Oct 28 2009
STATUS
approved