Hello, Please help me find the steps for this problem. The answer is shown but I'm lost on how they got that. Use the root test and show all your work. Thanks in advance.

Use the root test to determine if the following series converges or diverges. OO 17 E n= 1 (3 + (1)) 4n . . . Since the limit resulting from the root test is 81 the root test shows the series converges. (Simplify your answer. Type an exact answer.)