OFFSET
0,3
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (-1, 2, -2).
FORMULA
a(n) = (-1)^n*A077946(n). - R. J. Mathar, Feb 28 2019
MATHEMATICA
CoefficientList[Series[1/(1+x-2x^2+2x^3), {x, 0, 40}], x] (* or *) LinearRecurrence[ {-1, 2, -2}, {1, -1, 3}, 40] (* Harvey P. Dale, Sep 29 2018 *)
PROG
(PARI) Vec(1/(1+x-2*x^2+2*x^3)+O(x^40)) \\ Charles R Greathouse IV, Sep 26 2012
(Magma) R<x>:=PowerSeriesRing(Integers(), 40); Coefficients(R!( 1/(1+x-2*x^2+2*x^3) )); // G. C. Greubel, Jun 24 2019
(Sage) (1/(1+x-2*x^2+2*x^3)).series(x, 40).coefficients(x, sparse=False) # G. C. Greubel, Jun 24 2019
(GAP) a:=[1, 1, -3];; for n in [4..40] do a[n]:=-a[n-1]+2*a[n-2]-2*a[n-3]; od; a; # G. C. Greubel, Jun 24 2019
CROSSREFS
KEYWORD
sign,easy
AUTHOR
N. J. A. Sloane, Nov 17 2002
STATUS
approved