A070372 a(n) = 5^n mod 18.

1, 5, 7, 17, 13, 11, 1, 5, 7, 17, 13, 11, 1, 5, 7, 17, 13, 11, 1, 5, 7, 17, 13, 11, 1, 5, 7, 17, 13, 11, 1, 5, 7, 17, 13, 11, 1, 5, 7, 17, 13, 11, 1, 5, 7, 17, 13, 11, 1, 5, 7, 17, 13, 11, 1, 5, 7, 17, 13, 11, 1, 5, 7, 17, 13, 11, 1, 5, 7, 17, 13, 11, 1, 5, 7, 17, 13, 11, 1, 5, 7, 17, 13

Offset

0,2

Links

G. C. Greubel, Table of n, a(n) for n = 0..999

Index entries for linear recurrences with constant coefficients, signature (1,0,-1,1). [From R. J. Mathar, Apr 20 2010]

Formula

a(n) = (1/15)*{34*(n mod 6)+14*[(n+1) mod 6]+19*[(n+2) mod 6]-16*[(n+3) mod 6]+4*[(n+4) mod 6]-[(n+5) mod 6]}], with n>=0. - Paolo P. Lava, Feb 24 2010

From R. J. Mathar, Apr 20 2010: (Start)

a(n) = a(n-1) - a(n-3) + a(n-4).

G.f.: ( -1-4*x-2*x^2-11*x^3 ) / ( (x-1)*(1+x)*(x^2-x+1) ). (End)

a(n) = a(n-6). - G. C. Greubel, Mar 05 2016

Mathematica

PowerMod[5, Range[0, 150], 18]  (* Harvey P. Dale, Mar 24 2011 *)
Table[Mod[5^n, 18], {n, 0, 100}] (* G. C. Greubel, Mar 05 2016 *)

Prog

(Sage) [power_mod(5, n, 18) for n in range(0, 83)] # Zerinvary Lajos, Nov 26 2009
(PARI) a(n) = lift(Mod(5, 18)^n); \\ Michel Marcus, Mar 05 2016

Crossrefs

Cf. A000351.

Sequence in context: A060640 A064944 A341038 * A082818 A224070 A075089

Adjacent sequences: A070369 A070370 A070371 * A070373 A070374 A070375

Keyword

nonn,easy

Author

N. J. A. Sloane, May 12 2002

Status

approved