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A131724 Period 6: repeat [1, 9, 7, 13, 11, 9]. 1

%I

%S 1,9,7,13,11,9,1,9,7,13,11,9,1,9,7,13,11,9,1,9,7,13,11,9,1,9,7,13,11,

%T 9,1,9,7,13,11,9,1,9,7,13,11,9,1,9,7,13,11,9,1,9,7,13,11,9,1,9,7,13,

%U 11,9,1,9,7,13,11,9,1,9,7,13,11,9,1,9,7,13,11,9

%N Period 6: repeat [1, 9, 7, 13, 11, 9].

%H Vincenzo Librandi, <a href="/A131724/b131724.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,1).

%F a(n) = (1/9)*{17*(n mod 6)+8*[(n+1) mod 6]+8*[(n+2) mod 6]-4*[(n+3) mod 6]+8*[(n+4) mod 6]-7*[(n+5) mod 6]}. - _Paolo P. Lava_, Oct 02 2007

%F From _Wesley Ivan Hurt_, Jun 18 2016: (Start)

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

%F a(n) = a(n-6) for n>5.

%F a(n) = (25 - 6*cos(n*Pi) - 12*cos(n*Pi/3) - 4*cos(2*n*Pi/3) -2*sqrt(3)*sin(n*Pi/3) + 2*sqrt(3)*sin(2*n*Pi/3))/3. (End)

%p A131724:=n->[1, 9, 7, 13, 11, 9][(n mod 6)+1]: seq(A131724(n), n=0..100); # _Wesley Ivan Hurt_, Jun 18 2016

%t Flatten[Table[{1, 9, 7, 13, 11, 9}, {20}]] (* _Wesley Ivan Hurt_, Jun 18 2016 *)

%t PadRight[{}, 100, {1, 9, 7, 13, 11, 9}] (* _Vincenzo Librandi_, Jun 19 2016 *)

%o (MAGMA) &cat[[1, 9, 7, 13, 11, 9]: n in [0..20]]; // _Wesley Ivan Hurt_, Jun 18 2016

%K nonn,easy

%O 0,2

%A _Paul Curtz_, Sep 16 2007

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Last modified November 22 05:55 EST 2019. Contains 329388 sequences. (Running on oeis4.)