digitnPowers(2) should return a number.
    testString: assert(typeof digitnPowers(2) === 'number');
  - text: digitnPowers(2) should return 0.
    testString: assert(digitnPowers(2) == 0);
  - text: digitnPowers(3) should return 1301.
    testString: assert(digitnPowers(3) == 1301);
  - text: digitnPowers(4) should return 19316.
    testString: assert(digitnPowers(4) == 19316);
  - text: digitnPowers(5) should return 443839.
    testString: assert(digitnPowers(5) == 443839);
```