... 2001)almost-primes The almost -prime numbers have a limited number of prime factors. The 2-almost-primes have two prime factors (including duplicatedfactors) and are also called semiprimes: the 3-almost-primes ... be opposite to each other, the super-abundant and the deficient, are divided in their condition, which is inequal-ity, into the too much and the too little. In the case of the too much, is produced ... important as the discovery itself.(Gauss 1817) The study of the primes brings in every style and every level ofmathematical thinking, from the simplest pattern spotting (often mis-leading, as we...