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A133456
Period 18: repeat 3, 3, -5, 0, 3, -1, -3, 0, 7 followed by their negatives.
0
3, 3, -5, 0, 3, -1, -3, 0, 7, -3, -3, 5, 0, -3, 1, 3, 0, -7, 3, 3, -5, 0, 3, -1, -3, 0, 7, -3, -3, 5, 0, -3, 1, 3, 0, -7, 3, 3, -5, 0, 3, -1, -3, 0, 7, -3, -3, 5, 0, -3, 1, 3, 0, -7
OFFSET
0,1
FORMULA
First differences 1, 4, 7, 2, 2, 5, 4 = A133390.
a(n) = -a(n-9) for n > 8. G.f.: (7*x^8 - 3*x^6 - x^5 + 3*x^4 - 5*x^2 + 3*x + 3)/(x^9 + 1). - Chai Wah Wu, Jun 04 2016
PROG
(PARI) a(n)=[3, 3, -5, 0, 3, -1, -3, 0, 7][n%9+1]*(-1)^(n\9) \\ Charles R Greathouse IV, Jul 13 2016
CROSSREFS
Sequence in context: A348679 A011445 A197137 * A271710 A371659 A246005
KEYWORD
sign,easy
AUTHOR
Paul Curtz, Nov 27 2007
STATUS
approved