OFFSET
0,5
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (2,-2,2).
FORMULA
MATHEMATICA
LinearRecurrence[{2, -2, 2}, {1, 1, 0}, 50] (* or *) CoefficientList[
Series[(1-x)/(1-2*x+2*x^2-2*x^3), {x, 0, 50}], x] (* G. C. Greubel, Jun 27 2019 *)
PROG
(PARI) Vec((1-x)/(1-2*x+2*x^2-2*x^3)+O(x^50)) \\ Charles R Greathouse IV, Sep 26 2012
(Magma) R<x>:=PowerSeriesRing(Integers(), 50); Coefficients(R!( (1-x)/( 1-2*x+2*x^2-2*x^3) )); // G. C. Greubel, Jun 27 2019
(Sage) ((1-x)/(1-2*x+2*x^2-2*x^3)).series(x, 50).coefficients(x, sparse=False) # G. C. Greubel, Jun 27 2019
(GAP) a:=[1, 1, 0];; for n in [4..50] do a[n]:=2*(a[n-1]-a[n-2]+a[n-3]); od; a; # G. C. Greubel, Jun 27 2019
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Nov 17 2002
STATUS
approved