The coefficient of $(x^2)^n$ is $(n!)^2/(2n)!$. I did the problem and calculated the radius of convergence to be 2. But the book says it's 4. I'm having the same issue with similar problems where only even powers of $x$ are present. Am I doing something wrong?
2026-03-28 03:27:26.1774668446
Radius of convergence of this power series?
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