MathDB
Delightful Integers

Source: 2013 Baltic Way, Problem 16

December 31, 2013
inequalitiesnumber theory unsolvednumber theory

Problem Statement

We call a positive integer nn delightful if there exists an integer kk, 1<k<n1 < k < n, such that 1+2++(k1)=(k+1)+(k+2)++n1+2+\cdots+(k-1)=(k+1)+(k+2)+\cdots+n Does there exist a delightful number NN satisfying the inequalities 20132013<N20132013<20132013+4?2013^{2013}<\dfrac{N}{2013^{2013}}<2013^{2013}+4 ?