# For which n does 1+2+...+n divide 1*2+2*3+...(n-1)n

For which $n$ does $\sum_{i=1}^ni$ divide $\sum_{i=1}^n(i-1)i$ ?
$\frac{\sum_{i=1}^{n}i}{\sum_{i=1}^{n}(i-1)i}=\frac{\frac{n(n+1)}{2}}{\frac{n(n-1)(n+1)}{3}}=\frac{3}{2(n-1)}$