Don Larsen, David Wells, David Cone and Domingo German. The 30-year-old etched himself into Yankees and baseball history and joined an exclusive club on Wednesday night at Oakland-Alameda County ...

For n a positive integer, let σ(n) denote the sum of the divisors of n. The number n is said to be deficient perfect if σ(n)/n = (2x 1)/x for some x ∊ ℕ. We show that every perfect number has a ...