Consider the power series $$\sum_{n=1}^{\infty} \frac{2 \cdot 4 \cdot 6 \cdot \cdots \cdot (2n)}{1 \cdot 3 \cdot 5 \cdot \cdots \cdot (2n-1)}x^n.$$ Find the radius of convergence $R.$ If it is infinite, type "infinity" or "inf".
Answer: $R =$

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What is the interval of convergence?
Answer (in interval notation):

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