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A174784
Expansion of x*(1-x+x^3+x^4)/(1+x^6) (Period 12).
1
0, 1, -1, 0, 1, 1, 0, -1, 1, 0, -1, -1, 0, 1, -1, 0, 1, 1, 0, -1, 1, 0, -1, -1, 0, 1, -1, 0, 1, 1, 0, -1, 1, 0, -1, -1, 0, 1, -1, 0, 1, 1, 0, -1, 1, 0, -1, -1, 0, 1, -1, 0, 1, 1, 0, -1, 1, 0, -1, -1, 0, 1, -1, 0, 1, 1, 0, -1, 1, 0, -1, -1, 0, 1, -1, 0, 1, 1, 0, -1, 1, 0, -1, -1, 0, 1, -1, 0, 1, 1, 0
OFFSET
0,1
COMMENTS
Hankel transform of A174783 is -a(n).
FORMULA
a(n) = -cos(5*Pi*n/6)/3 + sin(5*Pi*n/6)/3 - cos(Pi*n/6)/3 + sin(Pi*n/6)/3 + 2*cos(Pi*n/2)/3 + 2*sin(Pi*n/2)/3.
G.f.: x*(1-x+x^3+x^4) / ( (1+x^2)*(x^4-x^2+1) ). - R. J. Mathar, Feb 10 2015
MATHEMATICA
LinearRecurrence[{0, 0, 0, 0, 0, -1}, {0, 1, -1, 0, 1, 1}, 100] (* or *) PadRight[ {}, 120, {0, 1, -1, 0, 1, 1, 0, -1, 1, 0, -1, -1}] (* Harvey P. Dale, Feb 25 2017 *)
CROSSREFS
Sequence in context: A284792 A094217 A280261 * A092220 A011655 A102283
KEYWORD
easy,sign
AUTHOR
Paul Barry, Mar 29 2010
STATUS
approved