doubleBasePalindromes(1000) debe devolver 1772.
testString: 'assert(doubleBasePalindromes(1000) == 1772, "doubleBasePalindromes(1000) should return 1772.");'
- text: doubleBasePalindromes(50000) debe devolver 105795.
testString: 'assert(doubleBasePalindromes(50000) == 105795, "doubleBasePalindromes(50000) should return 105795.");'
- text: doubleBasePalindromes(500000) debe devolver 286602.
testString: 'assert(doubleBasePalindromes(500000) == 286602, "doubleBasePalindromes(500000) should return 286602.");'
- text: doubleBasePalindromes(1000000) debe devolver 872187.
testString: 'assert(doubleBasePalindromes(1000000) == 872187, "doubleBasePalindromes(1000000) should return 872187.");'
```