A070361 a(n) = 3^n mod 41.

1, 3, 9, 27, 40, 38, 32, 14, 1, 3, 9, 27, 40, 38, 32, 14, 1, 3, 9, 27, 40, 38, 32, 14, 1, 3, 9, 27, 40, 38, 32, 14, 1, 3, 9, 27, 40, 38, 32, 14, 1, 3, 9, 27, 40, 38, 32, 14, 1, 3, 9, 27, 40, 38, 32, 14, 1, 3, 9, 27, 40, 38, 32, 14, 1, 3, 9, 27, 40, 38, 32, 14, 1, 3, 9, 27, 40, 38, 32

Offset: 0

Author

N. J. A. Sloane, May 12 2002

Keywords

• nonn
• easy

Links

• G. C. Greubel, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (1,0,0,-1,1).

Crossrefs

Cf. A000244.

Programs

Mathematica

PowerMod[3, Range[0,50], 41] (* or *) Table[Mod[3^n, 41], {n, 0, 100}] (* G. C. Greubel, Mar 09 2016 *)
LinearRecurrence[{1,0,0,-1,1},{1,3,9,27,40},100] (* Harvey P. Dale, Mar 27 2020 *)

PARI

a(n)=lift(Mod(3,41)^n) \\ Charles R Greathouse IV, Mar 22 2016

Formula

G.f.: (1+2*x+6*x^2+18*x^3+14*x^4)/ ((1-x) * (1+x^4)). - R. J. Mathar, Mar 13 2010

a(n) = a(n-2)+a(n-6)-a(n-4). - Vincenzo Librandi, Feb 06 2011

a(n) = a(n-8). - G. C. Greubel, Mar 09 2016