Question 12
(VIE 2) The polynomial $1976(x+x^2+\cdots+x^n)$ is decomposed into a sum of polynomials of the form $a_1x+a_2x^2+\cdots+a_nx^n$, where $a_1,a_2,\ldots,a_n$ are distinct positive integers not greater than $n$. Find all values of $n$ for which such a decomposition is possible.