cards with divisors of 6^{100}
Source: St. Petersburg 2019 9.4
May 2, 2019
number theoryreciprocal sumSumDivisorsIrreducible
Problem Statement
Olya wrote fractions of the form on cards, where is all possible divisors the numbers (including the unit and the number itself). These cards she laid out in some order. After that, she wrote down the number on the first card, then the sum of the numbers on the first and second cards, then the sum of the numbers on the first three cards, etc., finally, the sum of the numbers on all the cards. Every amount Olya recorded on the board in the form of irreducible fraction. What is the least different denominators could be on the numbers on the board?