在VScode上递推与递推记忆化运行结果一致 为什么会RE

n = int(input(""))

records = [0] * n
def num_2(n):

    if n == 1:
        return 1
    elif records[n - 1] != 0:
        return records[n - 1]
    else:
        record = sum([num_1(x) for x in range(1, n // 2 + 1)]) + 1
        records[n - 1] = record
        return record
    
print(num_2(n))