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A070361
a(n) = 3^n mod 41.
3
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
0,2
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
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 *)
PROG
(PARI) a(n)=lift(Mod(3, 41)^n) \\ Charles R Greathouse IV, Mar 22 2016
CROSSREFS
Cf. A000244.
Sequence in context: A018766 A036126 A045580 * A056024 A116475 A337948
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, May 12 2002
STATUS
approved