# How do you find the common ratio of 136,68,34,17,...?

${a}_{k} = 17 \cdot {2}^{k}$ for $k = 0 , \pm 1 , \pm 2 , \cdots$
${a}_{k} = 17 \cdot {2}^{k}$ for $k = 0 , \pm 1 , \pm 2 , \cdots$