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A070422
a(n) = 7^n mod 39.
3
1, 7, 10, 31, 22, 37, 25, 19, 16, 34, 4, 28, 1, 7, 10, 31, 22, 37, 25, 19, 16, 34, 4, 28, 1, 7, 10, 31, 22, 37, 25, 19, 16, 34, 4, 28, 1, 7, 10, 31, 22, 37, 25, 19, 16, 34, 4, 28, 1, 7, 10, 31, 22, 37, 25, 19, 16, 34, 4, 28, 1, 7, 10, 31, 22, 37, 25, 19, 16, 34, 4, 28, 1, 7, 10, 31
OFFSET
0,2
FORMULA
From R. J. Mathar, Apr 20 2010: (Start)
a(n) = a(n-2) - a(n-4) + a(n-6) - a(n-8) + a(n-10).
G.f.: ( -1-7*x-9*x^2-24*x^3-13*x^4-13*x^5-12*x^6-6*x^7-4*x^8-28*x^9 ) / ( (x-1)*(1+x)*(1+x+x^2)*(x^2-x+1)*(1-x^2+x^4) ). (End)
a(n) = a(n-12). - G. C. Greubel, Mar 22 2016
MATHEMATICA
PowerMod[7, Range[0, 50], 39] (* G. C. Greubel, Mar 22 2016 *)
PROG
(Sage) [power_mod(7, n, 39) for n in range(0, 76)] # Zerinvary Lajos, Nov 27 2009
(PARI) a(n)=lift(Mod(7, 39)^n) \\ Charles R Greathouse IV, Mar 22 2016
(Magma) [Modexp(7, n, 39): n in [0..100]]; // Bruno Berselli, Mar 22 2016
CROSSREFS
Sequence in context: A280966 A360430 A174466 * A102574 A317797 A284418
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, May 12 2002
STATUS
approved