A Faster Way to Compute Factors

A conceptually simple and straight-forward way to calculate the factors of a given number n, might look like the below code:

# ruby
def factors(n)
(1..n).select { |int| n % int == 0 }
end
// javascript
function factors(n) {
return Array(n).fill().map((_, idx) => idx + 1)
.filter(int => n % int === 0);
}

These code samples do the job. They iterate through an inclusive list of numbers 1 through n, selecting only those numbers by which n can be divided evenly. The returned result is an array of n's…