A168399 a(n) = 3^n mod 13.

1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9, 1, 3, 9

Offset

0,2

Comments

Equivalently: 3^(n+3*m) mod 13. - G. C. Greubel, Jul 20 2016

Links

Table of n, a(n) for n=0..92.

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

Formula

From R. J. Mathar, Apr 13 2010: (Start)

a(n) = a(n-3).

G.f.: (1 + 3*x + 9*x^2)/ ((1-x)*(1+x+x^2)). (End)

Mathematica

Table[Mod[3^n, 13], {n, 0, 50}] (* G. C. Greubel, Jul 20 *)

Prog

(Sage) [power_mod(3, n, 13)for n in range(0, 93)] #
(PARI) a(n)=lift(Mod(3, 13)^n) \\ Charles R Greathouse IV, Mar 22 2016
(Magma) [Modexp(3, n, 13): n in [0..110]]; // Vincenzo Librandi, Jul 21 2016

Crossrefs

Sequence in context: A304022 A103556 A254348 * A290375 A245081 A010631

Adjacent sequences: A168396 A168397 A168398 * A168400 A168401 A168402

Keyword

nonn,easy

Author

Zerinvary Lajos, Nov 25 2009

Status

approved