A137445 a(n) = 2a(n-1)-2a(n-2), with a(0)=3 and a(1)=2.

3, 2, -2, -8, -12, -8, 8, 32, 48, 32, -32, -128, -192, -128, 128, 512, 768, 512, -512, -2048, -3072, -2048, 2048, 8192, 12288, 8192, -8192, -32768, -49152, -32768, 32768, 131072, 196608, 131072, -131072, -524288, -786432, -524288, 524288

Offset

0,1

Links

Table of n, a(n) for n=0..38.

Index entries for linear recurrences with constant coefficients, signature (2,-2).

Formula

O.g.f.: (3-4x)/(1-2x+2x^2). a(n)=(-1)^(n+1)*A134142(n+1). - R. J. Mathar, May 01 2008

a(n) = (3/2 - I/2)*(1 - I)^n + (3/2 + I/2)*(1 + I)^n, n>=0. - Taras Goy, Apr 20 2019

Mathematica

LinearRecurrence[{2, -2}, {3, 2}, 40] (* Harvey P. Dale, May 03 2018 *)

Crossrefs

Sequence in context: A329956 A242703 A141456 * A195422 A176530 A011319

Adjacent sequences: A137442 A137443 A137444 * A137446 A137447 A137448

Keyword

sign

Author

Paul Curtz, Apr 18 2008

Extensions

More terms from R. J. Mathar, May 01 2008

Status

approved