A049071 Expansion of x*(3-2*x)/(1-x^2).

0, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3, -2, 3

Offset

0,2

Links

Table of n, a(n) for n=0..79.

B. R. Myers, On Spanning Trees, Weighted Compositions, Fibonacci Numbers, and Resistor Networks, SIAM Rev., 17 (1975), 465-474.

Index entries for linear recurrences with constant coefficients, signature (0,1).

Formula

a(n) = (1-5*(-1)^n)/2 for n>0. - Colin Barker, Jun 09 2015

a(n) = a(n-2) for n>2. - Colin Barker, Jun 09 2015

Mathematica

CoefficientList[Series[x (3-2x)/(1-x^2), {x, 0, 150}], x]  (* Harvey P. Dale, Mar 23 2011 *)

Prog

(PARI) Vec(x*(3-2*x)/(1-x^2)+O(x^99)) \\ Charles R Greathouse IV, Sep 27 2012

Crossrefs

Sequence in context: A095206 A344129 A308006 * A168330 A176059 A262785

Adjacent sequences: A049068 A049069 A049070 * A049072 A049073 A049074

Keyword

sign,easy

Author

N. J. A. Sloane

Status

approved