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 (1,-2,-1).
FORMULA
a(n) = (-1)^n * A077978(n). - G. C. Greubel, Jul 02 2019
MATHEMATICA
LinearRecurrence[{1, -2, -1}, {1, 1, -1}, 50] (* or *) CoefficientList[ Series[1/(1-x+2*x^2+x^3), {x, 0, 50}], x] (* G. C. Greubel, Jul 02 2019 *)
PROG
(PARI) Vec(1/(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+2*x^2+x^3) )); // G. C. Greubel, Jul 02 2019
(Sage) (1/(1-x+2*x^2+x^3)).series(x, 50).coefficients(x, sparse=False) # G. C. Greubel, Jul 02 2019
(GAP) a:=[1, 1, -1];; for n in [4..50] do a[n]:=a[n-1]-2*a[n-2]-a[n-3]; od; a; # G. C. Greubel, Jul 02 2019
CROSSREFS
KEYWORD
sign,easy
AUTHOR
N. J. A. Sloane, Nov 17 2002
STATUS
approved