A070378 a(n) = 5^n mod 28.

1, 5, 25, 13, 9, 17, 1, 5, 25, 13, 9, 17, 1, 5, 25, 13, 9, 17, 1, 5, 25, 13, 9, 17, 1, 5, 25, 13, 9, 17, 1, 5, 25, 13, 9, 17, 1, 5, 25, 13, 9, 17, 1, 5, 25, 13, 9, 17, 1, 5, 25, 13, 9, 17, 1, 5, 25, 13, 9, 17, 1, 5, 25, 13, 9, 17, 1, 5, 25, 13, 9, 17, 1, 5, 25, 13, 9, 17, 1, 5, 25, 13, 9

Offset

0,2

Links

Edward Jiang, Table of n, a(n) for n = 0..10000

Index entries for linear recurrences with constant coefficients, signature (1,-1,1,-1,1).

Formula

From R. J. Mathar, Apr 20 2010: (Start)

a(n) = a(n-1) - a(n-2) + a(n-3) - a(n-4) + a(n-5).

G.f.: ( -1-4*x-21*x^2+8*x^3-17*x^4 ) / ( (x-1)*(1+x+x^2)*(1-x+x^2) ). (End)

a(n) = a(n-6). - G. C. Greubel, Mar 13 2016

Mathematica

PowerMod[5, Range[0, 50], 28] (* G. C. Greubel, Mar 13 2016 *)

Prog

(Sage) [power_mod(5, n, 28) for n in range(0, 83)] # Zerinvary Lajos, Nov 26 2009
(PARI) a(n)=lift(Mod(5, 28)^n) \\ Charles R Greathouse IV, Mar 22 2016

Crossrefs

Sequence in context: A143254 A070385 A328756 * A070384 A337392 A070377

Adjacent sequences: A070375 A070376 A070377 * A070379 A070380 A070381

Keyword

nonn,easy

Author

N. J. A. Sloane, May 12 2002

Status

approved