A077917 Expansion of (1-x)^(-1)/(1+2*x-2*x^2).

1, -1, 5, -11, 33, -87, 241, -655, 1793, -4895, 13377, -36543, 99841, -272767, 745217, -2035967, 5562369, -15196671, 41518081, -113429503, 309895169, -846649343, 2313089025, -6319476735, 17265131521, -47169216511, 128868696065, -352075825151, 961889042433, -2627929735167

Offset: 0

Author

N. J. A. Sloane, Nov 17 2002

Keywords

• sign
• easy

Comments

Pisano period lengths: 1, 1, 6, 1, 24, 6, 48, 1, 18, 24, 5, 6, 12, 48, 24, 1,144, 18,180, 24,... - R. J. Mathar, Aug 10 2012

Links

• P. Z. Chinn, R. Grimaldi and S. Heubach, Tiling with Ls and Squares, J. Int. Sequences 10 (2007) #07.2.8.
• Index entries for linear recurrences with constant coefficients, signature (-1,4,-2)

Programs

PARI

Vec((1-x)^(-1)/(1+2*x-2*x^2)+O(x^99)) \\ Charles R Greathouse IV, Sep 24 2012

Formula

a(n+1)-a(n) = (-1)^(n+1)*A002605(n+2). - R. J. Mathar, Mar 14 2011