Iterating the Sum-of-Divisors Function
Iterating the Sum-of-Divisors Function
Let σ0(n) = n and σ m (n) = σ(σ m–1(n)), where m ≥ 1 and σ is the sum-of-divisors function. We say that n is (m, k)perfect if σ m (n) = kn. We have tabulated all (2,k)-perfect numbers up to 109 and all (3, k)- and (4, k)-perfect …