Sure, I can help you write a test case generator for the given problem statement "Formula for beginners". Let's break down the requirements and generate the test cases accordingly.

### Requirements:

1. Each dataset consists of a formula written in Reverse Polish Notation (RPN).
2. Each formula is a string of up to 80 characters consisting of integers and operation symbols separated by a single space.
3. There are no formulas that divide by 0 or a value close to 0.
4. The number of datasets is no more than 50.

### Operations in RPN:
- Addition: `+`
- Subtraction: `-`
- Multiplication: `*`
- Division: `/`

### Test Case Generator:

We will generate random formulas in RPN and ensure they are valid and do not perform invalid operations like division by zero.

```python
import random

def generate_rpn_expression(max_length=80):
    """Generate a valid RPN expression"""
    operators = ['+', '-', '*', '/']
    stack = []
    expression = []
    
    while len(expression) < max_length:
        if len(stack) < 2 or (random.random() > 0.5 and len(stack) < max_length - len(expression) - 1):
            # Push a number onto the stack
            num = random.randint(-10**4, 10**4)
            stack.append(num)
            expression.append(str(num))
        else:
            # Pop two numbers and push an operator
            if len(stack) < 2:
                break
            b = stack.pop()
            a = stack.pop()
            operator = random.choice(operators)
            if operator == '/' and b == 0:
                # Prevent division by zero
                b = random.randint(1, 10**4)
            result = eval(f"{a} {operator} {b}")
            stack.append(result)
            expression.append(operator)
    
    return ' '.join(expression)

def tcgen():
    num_datasets = random.randint(1, 50)
    test_cases = [generate_rpn_expression() for _ in range(num_datasets)]
    return test_cases

# Example of generating test cases
if __name__ == "__main__":
    test_cases = tcgen()
    for test_case in test_cases:
        print(test_case)
```

### Explanation:
1. **generate_rpn_expression**: Generates a single valid RPN expression.
   - It uses a stack to maintain valid intermediate states.
   - It ensures that we don't perform division by zero.
   - It keeps the length of the expression within a specified maximum length (default 80 characters).

2. **tcgen**: Generates a list of RPN expressions.
   - It randomly determines the number of datasets (between 1 and 50).
   - It generates the required number of valid RPN expressions.

This generator ensures that each test case follows the problem constraints and is ready for use in testing the RPN evaluation program.