A070405 a(n) = 7^n mod 13.

1, 7, 10, 5, 9, 11, 12, 6, 3, 8, 4, 2, 1, 7, 10, 5, 9, 11, 12, 6, 3, 8, 4, 2, 1, 7, 10, 5, 9, 11, 12, 6, 3, 8, 4, 2, 1, 7, 10, 5, 9, 11, 12, 6, 3, 8, 4, 2, 1, 7, 10, 5, 9, 11, 12, 6, 3, 8, 4, 2, 1, 7, 10, 5, 9, 11, 12, 6, 3, 8, 4, 2, 1, 7, 10, 5, 9, 11, 12, 6, 3, 8, 4, 2, 1, 7, 10, 5, 9, 11, 12

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,-1,1).

Formula

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

a(n) = a(n-1) - a(n-6) + a(n-7).

G.f.: ( -1-6*x-3*x^2+5*x^3-4*x^4-2*x^5-2*x^6 ) / ( (x-1)*(x^2+1)*(x^4-x^2+1) ). (End)

a(n) = a(n-12). - G. C. Greubel, Mar 20 2016

Mathematica

PowerMod[7, Range[0, 90], 13] (* or *) LinearRecurrence[{1, 0, 0, 0, 0, -1, 1}, {1, 7, 10, 5, 9, 11, 12}, 100] (* Harvey P. Dale, May 20 2014 *)

Prog

(Sage) [power_mod(7, n, 13) for n in range(0, 91)] # Zerinvary Lajos, Nov 03 2009
(PARI) a(n) = lift(Mod(7, 13)^n); \\ Altug Alkan, Mar 20 2016
(Magma) [Modexp(7, n, 13): n in [0..100]]; // Bruno Berselli, Mar 22 2016

Crossrefs

Sequence in context: A122577 A180732 A266551 * A377931 A010730 A225694

Adjacent sequences: A070402 A070403 A070404 * A070406 A070407 A070408

Keyword

nonn,easy

Author

N. J. A. Sloane, May 12 2002

Status

approved