What is the radius of convergence for ∑n=0∞x2nn!\sum_{n=0}^{\infty} \frac{x^{2n}}{n!}∑n=0∞n!x2n?
R=1R=1R=1
R=1R=\sqrt{1}R=1
R=∞R=\inftyR=∞
R=0R=0R=0