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

Author

Roger L. Bagula, May 30 2005

Keywords

• sign
• easy
• less

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).

Crossrefs

Cf. A001076, A001353.

Programs

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

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 *)

PARI

x='x+O('x^30); Vec(-x/(1-4*x+x^2)) \\ G. C. Greubel, Feb 05 2018

Formula

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

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

Extensions

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

New name from Joerg Arndt, Sep 22 2023