The sum of the squares of the first ten natural numbers is,
1^2+2^2+...+10^2 = 385
The square of the sum of the first ten natural numbers is,
(1+2+...+10)^2 = 55^2 = 3025
Hence 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 one hundred natural numbers and the square of the sum.
There are straightforward formulas for \sum_{k=1}^n k^2, but it's so
simple in this case to use brute force that I won't bother looking
them up.