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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 (list; graph; refs; listen; history; text; internal format)
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 (2, -2, 1).

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) = (1/15)*{61*(n mod 6)+71*[(n+1) mod 6]+31*[(n+2) mod 6]-19*[(n+3) mod 6]-29*[(n+4) mod 6]+11*[(n+5) mod 6]}, with n>=0. - Paolo P. Lava, Apr 16 2010

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

Adjacent sequences:  A070385 A070386 A070387 * A070389 A070390 A070391

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, May 12 2002

STATUS

approved

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Last modified August 3 02:48 EDT 2021. Contains 346435 sequences. (Running on oeis4.)