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A070389
a(n) = 5^n mod 43.
3
1, 5, 25, 39, 23, 29, 16, 37, 13, 22, 24, 34, 41, 33, 36, 8, 40, 28, 11, 12, 17, 42, 38, 18, 4, 20, 14, 27, 6, 30, 21, 19, 9, 2, 10, 7, 35, 3, 15, 32, 31, 26, 1, 5, 25, 39, 23, 29, 16, 37, 13, 22, 24, 34, 41, 33, 36, 8, 40, 28, 11, 12, 17, 42, 38, 18, 4, 20, 14, 27, 6, 30, 21, 19
OFFSET
0,2
LINKS
Index entries for linear recurrences with constant coefficients, signature (1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 1).
FORMULA
From R. J. Mathar, Apr 20 2010: (Start)
a(n) = a(n-1) - a(n-21) + a(n-22).
G.f.: ( -1-4*x -20*x^2 -14*x^3 +16*x^4 -6*x^5 +13*x^6-21*x^7 +24*x^8 -9*x^9 -2*x^10 -10*x^11 -7*x^12 +8*x^13 -3*x^14 +28*x^15 -32*x^16 +12*x^17 +17*x^18 -x^19 -5*x^20 -26*x^21 ) / ( (x-1)*(1+x)*(x^2-x+1)*(x^6-x^5+x^4-x^3+x^2-x+1)*(x^12+x^11-x^9-x^8+x^6-x^4-x^3+x+1) ). (End)
a(n) = a(n-42). - G. C. Greubel, Mar 16 2016
MATHEMATICA
PowerMod[5, Range[0, 50], 43] (* G. C. Greubel, Mar 16 2016 *)
PROG
(Sage) [power_mod(5, n, 43) for n in range(0, 74)] # Zerinvary Lajos, Nov 26 2009
(PARI) a(n)=lift(Mod(5, 43)^n) \\ Charles R Greathouse IV, Mar 22 2016
(Magma) [Modexp(5, n, 43): n in [0..80]]; // Bruno Berselli, Mar 22 2016
CROSSREFS
Sequence in context: A361615 A070390 A018724 * A098993 A099799 A093534
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, May 12 2002
STATUS
approved