A135694 - OEIS

A135694

Period 6: repeat [1, -1, -1, -1, 0, 2].

1, -1, -1, -1, 0, 2, 1, -1, -1, -1, 0, 2, 1, -1, -1, -1, 0, 2, 1, -1, -1, -1, 0, 2, 1, -1, -1, -1, 0, 2, 1, -1, -1, -1, 0, 2, 1, -1, -1, -1, 0, 2, 1, -1, -1, -1, 0, 2, 1, -1, -1, -1, 0, 2, 1, -1, -1, -1, 0, 2, 1, -1, -1, -1, 0, 2, 1, -1, -1, -1, 0, 2, 1, -1, -1, -1, 0, 2, 1, -1, -1, -1, 0, 2

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OFFSET

0,6

LINKS

Table of n, a(n) for n=0..83.

Index entries for linear recurrences with constant coefficients, signature (0,-1,0,-1).

FORMULA

From R. J. Mathar, Mar 31 2008: (Start)

a(n) = a(n-6) for n>5. a(n) = -a(n-2) - a(n-4) for n>3.

a(n) = (A119910(n+3) - A049347(n+1))/2 for n>0.

G.f.: (1-x-2*x^3)/((x^2-x+1)*(x^2+x+1)). (End)

a(n) = (3*cos(n*Pi/3) - 8*sqrt(3)*cos(n*Pi/6)^3*sin(n*Pi/6))/3. - Wesley Ivan Hurt, Jun 22 2016