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URL: https://oeis.org/A077959

⇱ A077959 - OEIS

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A077959
Expansion of 1/(1+2*x^3).
2
1, 0, 0, -2, 0, 0, 4, 0, 0, -8, 0, 0, 16, 0, 0, -32, 0, 0, 64, 0, 0, -128, 0, 0, 256, 0, 0, -512, 0, 0, 1024, 0, 0, -2048, 0, 0, 4096, 0, 0, -8192, 0, 0, 16384, 0, 0, -32768, 0, 0, 65536, 0, 0, -131072, 0, 0, 262144, 0, 0, -524288, 0, 0, 1048576, 0, 0, -2097152, 0, 0, 4194304, 0, 0, -8388608, 0
OFFSET
0,4
FORMULA
a(0)=1, a(1)=0, a(2)=0, a(n) = -2*a(n-3). - Harvey P. Dale, Dec 19 2012
a(n) = (-1)^n * A077958(n). - R. J. Mathar, Mar 04 2018
MATHEMATICA
CoefficientList[Series[1/(1+2x^3), {x, 0, 80}], x] (* or *) LinearRecurrence[ {0, 0, -2}, {1, 0, 0}, 80] (* Harvey P. Dale, Dec 19 2012 *)
PROG
(PARI) Vec(1/(1+2*x^3)+O(x^80)) \\ Charles R Greathouse IV, Sep 27 2012
(Magma) R<x>:=PowerSeriesRing(Integers(), 80); Coefficients(R!( 1/(1+2*x^3) )); // G. C. Greubel, Jun 23 2019
(SageMath) (1/(1+2*x^3)).series(x, 80).coefficients(x, sparse=False) # G. C. Greubel, Jun 23 2019
CROSSREFS
Cf. A077958.
Sequence in context: A136337 A028601 A077958 * A392074 A022002 A392042
KEYWORD
sign,easy
AUTHOR
N. J. A. Sloane, Nov 17 2002
STATUS
approved