MathDB
O 39

Source:

May 25, 2007
number theoryleast common multiplegreatest common divisorprime factorization

Problem Statement

Find the smallest positive integer nn for which there exist nn different positive integers a1,a2,,ana_{1}, a_{2}, \cdots, a_{n} satisfying [*] lcm(a1,a2,,an)=1985\text{lcm}(a_1,a_2,\cdots,a_n)=1985,[*] for each i,j{1,2,,n}i, j \in \{1, 2, \cdots, n \}, gcd(ai,aj)1gcd(a_i,a_j)\not=1, [*] the product a1a2ana_{1}a_{2} \cdots a_{n} is a perfect square and is divisible by 243243, and find all such nn-tuples (a1,,an)(a_{1}, \cdots, a_{n}).