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A135694
Period 6: repeat [1, -1, -1, -1, 0, 2].
1
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
OFFSET
0,6
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
MAPLE
A135694 := proc(n) op((n mod 6)+1, [1, -1, -1, -1, 0, 2]) ; end: seq(A135694(n), n=0..150) ; # R. J. Mathar, Feb 07 2009
MATHEMATICA
PadRight[{}, 100, {1, -1, -1, -1, 0, 2}] (* Wesley Ivan Hurt, Jun 22 2016 *)
PROG
(Magma) &cat [[1, -1, -1, -1, 0, 2]^^20]; // Wesley Ivan Hurt, Jun 22 2016
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Paul Curtz, Feb 24 2008
EXTENSIONS
More periods from R. J. Mathar, Feb 07 2009
STATUS
approved