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A070388
a(n) = 5^n mod 42.
1
1, 5, 25, 41, 37, 17, 1, 5, 25, 41, 37, 17, 1, 5, 25, 41, 37, 17, 1, 5, 25, 41, 37, 17, 1, 5, 25, 41, 37, 17, 1, 5, 25, 41, 37, 17, 1, 5, 25, 41, 37, 17, 1, 5, 25, 41, 37, 17, 1, 5, 25, 41, 37, 17, 1, 5, 25, 41, 37, 17, 1, 5, 25, 41, 37, 17, 1, 5, 25, 41, 37, 17, 1, 5, 25, 41, 37, 17
OFFSET
0,2
FORMULA
From R. J. Mathar, Dec 16 2009: (Start)
a(n)= 2*a(n-1) - 2*a(n-2) + a(n-3).
G.f.: (1+3*x+17*x^2)/((1-x)*(x^2-x+1)). (End)
a(n) = a(n-1) - a(n-2) + 21, n>=2. - R. J. Mathar, Nov 07 2015
a(n) = a(n-6). - G. C. Greubel, Mar 16 2016
MATHEMATICA
PowerMod[5, Range[0, 50], 42] (* G. C. Greubel, Mar 16 2016 *)
PROG
(Sage) [power_mod(5, n, 42) for n in range(0, 78)] # Zerinvary Lajos, Nov 26 2009
(PARI) a(n) = lift(Mod(5, 42)^n); \\ Altug Alkan, Mar 16 2016
CROSSREFS
Sequence in context: A098993 A099799 A093534 * A250314 A293571 A294256
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, May 12 2002
STATUS
approved