A078037 Expansion of (1-x)/(1+2*x^2+2*x^3).

1, -1, -2, 0, 6, 4, -12, -20, 16, 64, 8, -160, -144, 304, 608, -320, -1824, -576, 4288, 4800, -7424, -18176, 5248, 51200, 25856, -112896, -154112, 174080, 534016, -39936, -1416192, -988160, 2912256, 4808704, -3848192, -15441920, -1921024, 38580224, 34725888, -73318400, -146612224

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 (0,-2,-2).

Mathematica

LinearRecurrence[{0, -2, -2}, {1, -1, -2}, 50] (* or *) CoefficientList[ Series[(1-x)/(1+2*x^2+2*x^3), {x, 0, 50}], x] (* G. C. Greubel, Jun 24 2019 *)

Prog

(PARI) Vec((1-x)/(1+2*x^2+2*x^3)+O(x^50)) \\ Charles R Greathouse IV, Sep 27 2012
(Magma) R<x>:=PowerSeriesRing(Integers(), 50); Coefficients(R!( (1-x)/(1+2*x^2+2*x^3) )); // G. C. Greubel, Jun 24 2019
(Sage) ((1-x)/(1+2*x^2+2*x^3)).series(x, 50).coefficients(x, sparse=False) # G. C. Greubel, Jun 24 2019
(GAP) a:=[1, -1, -2];; for n in [4..50] do a[n]:=-2*(a[n-2]+a[n-3]); od; a; # G. C. Greubel, Jun 24 2019

Crossrefs

Cf. A077964.

Sequence in context: A115879 A115880 A335728 * A088508 A142457 A100711

Adjacent sequences: A078034 A078035 A078036 * A078038 A078039 A078040

Keyword

sign,easy

Author

N. J. A. Sloane, Nov 17 2002

Status

approved