2018 preRMO p22, k=sum of no in partition of {1, 2, ..., 20}, good integer
Source:
August 8, 2019
SetsSubsetspartitionsSumcombinatorics
Problem Statement
A positive integer is said to be good if there exists a partition of into disjoint proper subsets such that the sum of the numbers in each subset of the partition is . How many good numbers are there?