A070336 a(n) = 2^n mod 25.

1, 2, 4, 8, 16, 7, 14, 3, 6, 12, 24, 23, 21, 17, 9, 18, 11, 22, 19, 13, 1, 2, 4, 8, 16, 7, 14, 3, 6, 12, 24, 23, 21, 17, 9, 18, 11, 22, 19, 13, 1, 2, 4, 8, 16, 7, 14, 3, 6, 12, 24, 23, 21, 17, 9, 18, 11, 22, 19, 13, 1, 2, 4, 8, 16, 7, 14, 3, 6, 12, 24, 23, 21, 17

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, 0, 0, 0, 0, -1, 1).

Formula

From R. J. Mathar, Apr 13 2010: (Start)

a(n) = a(n-1) - a(n-10) + a(n-11).

G.f.: (1+x+2*x^2+4*x^3+8*x^4-9*x^5+7*x^6 -11*x^7+3*x^8+6*x^9+13*x^10)/ ((1-x) * (x^ 2+1) * (x^8-x^6+x^4-x^2+1)). (End)

a(n) = a(n-20). - Franz Vrabec, Dec 06 2011

Mathematica

PowerMod[2, Range[0, 75], 25] (* or *) LinearRecurrence[ {1, 0, 0, 0, 0, 0, 0, 0, 0, -1, 1}, {1, 2, 4, 8, 16, 7, 14, 3, 6, 12, 24}, 75] (* Harvey P. Dale, Jun 20 2011 *)

Prog

(Sage) [power_mod(2, n, 25)for n in range(0, 74)] # Zerinvary Lajos, Nov 03 2009
(PARI) a(n)=lift(Mod(2, 25)^n) \\ Charles R Greathouse IV, Mar 22 2016
(GAP) a:=List([0..70], n->PowerMod(2, n, 25));; Print(a); # Muniru A Asiru, Jan 28 2019

Crossrefs

Sequence in context: A333492 A228845 A228846 * A348433 A053026 A375635

Adjacent sequences: A070333 A070334 A070335 * A070337 A070338 A070339

Keyword

nonn,easy

Author

N. J. A. Sloane, May 12 2002

Status

approved