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A070378 a(n) = 5^n mod 28. 1
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 (list; graph; refs; listen; history; text; internal format)
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

a(n) = (1/9)*{31*(n mod 6)-5*[(n+1) mod 6]+13*[(n+2) mod 6]+25*[(n+3) mod 6]-23*[(n+4) mod 6]+[(n+5) mod 6]}], with n>=0. - Paolo P. Lava, Feb 24 2010

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 xrange(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: A070379 A143254 A070385 * A070384 A070377 A070383

Adjacent sequences:  A070375 A070376 A070377 * A070379 A070380 A070381

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, May 12 2002

STATUS

approved

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Last modified May 29 14:18 EDT 2017. Contains 287247 sequences.