Kata

The sum of the squares of the first ten natural numbers is:

1 * 1 + 2 * 2 + ... + 10 * 10 = 385

The square of the sum of the first ten natural numbers is:

(1 + 2 + ... + 10) * (1 + 2 + ... + 10) = 55 * 55 = 3025

The difference between the sum of the squares of the first ten natural numbers and the square of the sum is:

3025 − 385 = 2640

Find the difference between the sum of the squares of the first n natural numbers (n > 0) and the square of the sum, and then return the sum of the square of its digits.

e.g 2640 --> 2 * 2 + 6 * 6 + 4 * 4 + 0 * 0 = 56