Certainly! Here's a test case generator for the problem "What Goes Up Must Come Down":

```python
import random

def tcgen():
    # Define the range for n
    n = random.randint(1, 100000)
    
    # Generate a list of n integers with values between 1 and 100000
    a = [random.randint(1, 100000) for _ in range(n)]
    
    return n, a

# Function to print the generated test case
def print_test_case():
    n, a = tcgen()
    print(n)
    print(" ".join(map(str, a)))

# Example usage
print_test_case()
```

This generator produces a random test case within the constraints specified in the problem statement. Each execution of `print_test_case()` will print a new test case with:
- An integer \( n \) representing the number of cards.
- A list of \( n \) random integers between 1 and 100000 representing the numbers on the cards.

You can run `print_test_case()` multiple times to generate different test cases. If you need specific test cases to test edge cases or other conditions, you can manually set values for `n` and `a` in the `tcgen` function.