pandigitalPrime(4) debe devolver 4231.
    testString: 'assert(pandigitalPrime(4) == 4231, "pandigitalPrime(4) should return 4231.");'
  - text: pandigitalPrime(7) debe devolver 7652413.
    testString: 'assert(pandigitalPrime(7) == 7652413, "pandigitalPrime(7) should return 7652413.");'
```