OFFSET
0,4
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (0,-1,3,-1).
MATHEMATICA
LinearRecurrence[{0, -1, 3, -1}, {1, 0, -1, 3}, 50] (* or *) CoefficientList[ Series[1/((1-x)*(1+x+2*x^2-x^3)), {x, 0, 50}], x] (* G. C. Greubel, Jul 02 2019 *)
PROG
(PARI) Vec(1/((1-x)*(1+x+2*x^2-x^3))+O(x^50)) \\ Charles R Greathouse IV, Sep 27 2012
(Magma) R<x>:=PowerSeriesRing(Integers(), 50); Coefficients(R!( 1/((1-x)*(1+x+2*x^2-x^3)) )); // G. C. Greubel, Jul 02 2019
(Sage) (1/((1-x)*(1+x+2*x^2-x^3))).series(x, 50).coefficients(x, sparse=False) # G. C. Greubel, Jul 02 2019
(GAP) a:=[1, 0, -1, 3];; for n in [4..50] do a[n]:=-a[n-2]+3*a[n-3]-a[n-4]; od; a; # G. C. Greubel, Jul 02 2019
CROSSREFS
KEYWORD
sign,easy
AUTHOR
N. J. A. Sloane, Nov 17 2002
STATUS
approved