BOJ - 9546 - 3000번 버스

def solution():
    T = int(input())

    for _ in range(T):
        stop = int(input())
        person = 1
        for i in range(stop - 1):
            person = person * 2 + 1
        print(person)

solution()

https://www.acmicpc.net/problem/9546