%I #24 Sep 25 2024 23:12:57
%S 1,9,-7,3,5,1,9,-7,3,5,1,9,-7,3,5,1,9,-7,3,5,1,9,-7,3,5,1,9,-7,3,5,1,
%T 9,-7,3,5,1,9,-7,3,5,1,9,-7,3,5,1,9,-7,3,5,1,9,-7,3,5,1,9,-7,3,5,1,9,
%U -7,3,5,1,9,-7,3,5,1,9,-7,3,5,1,9,-7,3,5,1,9,-7,3,5,1,9,-7,3,5,1,9,-7,3,5,1
%N Period 5: repeat [1, 9, -7, 3, 5].
%H <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,1).
%F a(n) == 9a(n-1) mod 11.
%F O.g.f.: -(1+9*x-7*x^2+3*x^3+5*x^4)/((x-1)*(1+x+x^2+x^3+x^4)). - _R. J. Mathar_, Jan 07 2008
%p A135449 := proc(n) op((n mod 5)+1,[1,9,-7,3,5]) ; end: seq(A135449(n),n=0..150) ; # _R. J. Mathar_, Feb 07 2009
%o (PARI) a(n)=[1,9,-7,3,5][n%5+1] \\ _Charles R Greathouse IV_, Jun 02 2011
%K sign,easy,less
%O 0,2
%A _Paul Curtz_, Dec 14 2007
%E More periods from _R. J. Mathar_, Feb 07 2009