Start with a set of a few distinct natural numbers.
For any 2 members, add their least common multiple to the set, if and only if it was not already in the set.
Continue the task until it cannot be done.
Call the result a final list.

Examples:
a. (2,4,8,16) a is a final list.
b. (2,3,4,6) will become a final list once we add number 12 to the set.

What can be the longest final list, if the initial set had 10 distinct numbers?

(In reply to D1 (spoiler) by Steve Herman)

.....he full set is the product of the numbers in any non-empty subset of the 10 primeS

Posted by Ady TZIDON on 2018-01-28 09:43:57