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A131193
Period 6: repeat [0, 1, -3, 3, -1, 0].
2
0, 1, -3, 3, -1, 0, 0, 1, -3, 3, -1, 0, 0, 1, -3, 3, -1, 0, 0, 1, -3, 3, -1, 0, 0, 1, -3, 3, -1, 0, 0, 1, -3, 3, -1, 0, 0, 1, -3, 3, -1, 0, 0, 1, -3, 3, -1, 0, 0, 1, -3, 3, -1, 0, 0, 1, -3, 3, -1, 0, 0, 1, -3, 3, -1, 0, 0, 1, -3, 3, -1, 0, 0, 1, -3, 3, -1, 0, 0, 1, -3, 3, -1, 0
OFFSET
0,3
FORMULA
G.f.: x*(x-1)^2/((x+1)*(x^2-x+1)*(x^2+x+1)). - R. J. Mathar, Nov 14 2007
From Wesley Ivan Hurt, Jun 20 2016: (Start)
a(n) + a(n-1) + a(n-2) + a(n-3) + a(n-4) + a(n-5) = 0 for n>4.
a(n) = sin(n*Pi/6) * (2*sqrt(3)*cos(n*Pi/6) + 3*sqrt(3)*cos(n*Pi/2) - sin(n*Pi/2) + 8*sin(5*n*Pi/6))/3. (End)
MAPLE
A131193:=n->[0, 1, -3, 3, -1, 0][(n mod 6)+1]: seq(A131193(n), n=0..100); # Wesley Ivan Hurt, Jun 20 2016
MATHEMATICA
PadRight[{}, 100, {0, 1, -3, 3, -1, 0}] (* Wesley Ivan Hurt, Jun 20 2016 *)
PROG
(Magma) &cat [[0, 1, -3, 3, -1, 0]^^20]; // Wesley Ivan Hurt, Jun 20 2016
CROSSREFS
Sequence in context: A356326 A261477 A205826 * A350479 A130632 A229158
KEYWORD
sign,easy
AUTHOR
Paul Curtz, Sep 26 2007
STATUS
approved