A070389 a(n) = 5^n mod 43.

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

G. C. Greubel, Table of n, a(n) for n = 0..1000

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

Adjacent sequences: A070386 A070387 A070388 * A070390 A070391 A070392

Keyword

nonn,easy

Author

N. J. A. Sloane, May 12 2002

Status

approved