What is the generating function for the sequence an=2na_n = 2^nan=2n?
A(x)=11−2xA(x) = \frac{1}{1-2x}A(x)=1−2x1
A(x)=11+2xA(x) = \frac{1}{1+2x}A(x)=1+2x1
A(x)=x1−2xA(x) = \frac{x}{1-2x}A(x)=1−2xx
A(x)=12−xA(x) = \frac{1}{2-x}A(x)=2−x1