Find n
Source: China TST 2004 Quiz
February 1, 2009
algebra unsolvedalgebra
Problem Statement
Find all positive integer satisfying the following condition: There exist positive integers , , , , a_{m\minus{}1}, such that \displaystyle n \equal{} \sum_{i\equal{}1}^{m\minus{}1} a_i(m\minus{}a_i), where , , , a_{m\minus{}1} may not distinct and 1 \leq a_i \leq m\minus{}1.