A133511 a(n) = 3 A113405(n)- A113405(n+1).

0, 0, -1, 1, 2, 5, 7, 14, 27, 57, 114, 229, 455, 910, 1819, 3641, 7282, 14565, 29127, 58254, 116507, 233017, 466034, 932069, 1864135, 3728270, 7456539, 14913081, 29826162, 59652325, 119304647, 238609294, 477218587, 954437177, 1908874354, 3817748709, 7635497415

Offset: 0

Author

Paul Curtz, Nov 30 2007

Keywords

• sign

Formula

2a(n)-a(n+1)=A133513(n).

A113405(n)-a(n)=A131531(n).

O.g.f.: x^2(3x-1)/((1-2x)(1+x)(1-x+x^2)). - R. J. Mathar, Jul 22 2008

a(n+2)=4*(2^n-(-1)^n)/9+A117373(n+2)/3. [From R. J. Mathar, Jul 20 2009]

Extensions

Edited and extended by R. J. Mathar, Jul 22 2008