An aliquot sequence is a sequence of integers, built with the sigma function . Normally an aliquot sequence ends in a prime.
Different sequences can come together and end in the same prime.
This was first published by the Belgian mathematician Eug ne Catalan in the year 1888. Up to now it is not possible to certify the Catalan conjecture. An ending aliquot sequence is a so called terminating sequence . Normally the end of an aliquot sequence is a prime. Instead of a prime an aliquot sequence can end in a cycle , too.