A106707 a(n) = -A001353(n).

0, -1, -4, -15, -56, -209, -780, -2911, -10864, -40545, -151316, -564719, -2107560, -7865521, -29354524, -109552575, -408855776, -1525870529, -5694626340, -21252634831, -79315912984, -296011017105, -1104728155436, -4122901604639, -15386878263120, -57424611447841

Offset

0,3

Links

G. C. Greubel, Table of n, a(n) for n = 0..1000

Tanya Khovanova, Recursive Sequences

Index entries for linear recurrences with constant coefficients, signature (4,-1).

Formula

G.f.: -x/(1-4*x+x^2).

a(n) = 4*a(n-1) - a(n-2); a(0)=0, a(1)=-1.

Maple

a[0]:=0: a[1]:=-1: for n from 2 to 27 do a[n]:=4*a[n-1]-a[n-2] od: seq(a[n], n=0..27);

Mathematica

LinearRecurrence[{4, -1}, {0, -1}, 30] (* Harvey P. Dale, Nov 01 2019 *)

Prog

(PARI) x='x+O('x^30); Vec(-x/(1-4*x+x^2)) \\ G. C. Greubel, Feb 05 2018
(Magma) I:=[0, -1]; [n le 2 select I[n] else 4*Self(n-1) - Self(n-2): n in [1..30]]; // G. C. Greubel, Feb 05 2018

Crossrefs

Cf. A001076, A001353.

Sequence in context: A191606 A242495 A221859 * A125905 A195503 A001353

Adjacent sequences: A106704 A106705 A106706 * A106708 A106709 A106710

Keyword

sign,easy,less

Author

Roger L. Bagula, May 30 2005

Extensions

Edited by N. J. A. Sloane, Apr 30 2006

New name from Joerg Arndt, Sep 22 2023

Status

approved