A167129 n^7 mod 21.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20

Offset

0,3

Comments

Equivalently: n^(6*m+7) mod 21. - G. C. Greubel, Jun 04 2016

Links

Table of n, a(n) for n=0..83.

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

Sequence in context: A121761 A056963 A291769 * A348287 A328447 A107602

Adjacent sequences: A167126 A167127 A167128 * A167130 A167131 A167132

Keyword

nonn,easy

Author

Zerinvary Lajos, Oct 28 2009

Status

approved