https://scienceblogs.com/evolutionblog/2011/05/09/monday-math-proving-eulers-for
Monday Math: Proving Euler's Formula for Perfect Numbers | ScienceBlogs
In last week's post we discussed perfect numbers. These were numbers, like 6, 28 and 496, that are equal to the sums of their proper divisors. We referred to...
euler s formulaperfect numbersmondaymathproving