A070411 a(n) = 7^n mod 26.

1, 7, 23, 5, 9, 11, 25, 19, 3, 21, 17, 15, 1, 7, 23, 5, 9, 11, 25, 19, 3, 21, 17, 15, 1, 7, 23, 5, 9, 11, 25, 19, 3, 21, 17, 15, 1, 7, 23, 5, 9, 11, 25, 19, 3, 21, 17, 15, 1, 7, 23, 5, 9, 11, 25, 19, 3, 21, 17, 15, 1, 7, 23, 5, 9, 11, 25, 19, 3, 21, 17, 15, 1, 7, 23, 5, 9, 11, 25, 19, 3

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). - R. J. Mathar, Apr 20 2010

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-16*x^2+18*x^3-4*x^4-2*x^5-15*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, 80], 26] (* or *) LinearRecurrence[{1, 0, 0, 0, 0, -1, 1}, {1, 7, 23, 5, 9, 11, 25}, 81] (* Harvey P. Dale, Dec 26 2011 *)

Prog

(Sage) [power_mod(7, n, 26)for n in range(0, 81)] # Zerinvary Lajos, Nov 27 2009
(PARI) a(n) = lift(Mod(7, 26)^n); \\ Altug Alkan, Mar 20 2016
(Magma) [Modexp(7, n, 26): n in [0..100]]; // Bruno Berselli, Mar 22 2016

Crossrefs

Sequence in context: A067959 A273216 A367002 * A340631 A367003 A167224

Adjacent sequences: A070408 A070409 A070410 * A070412 A070413 A070414

Keyword

nonn

Author

N. J. A. Sloane, May 12 2002

Status

approved