A variable X takes values $0, 0, 2, 6, 12, 20, \dots, n(n-1)$ with frequencies $\binom{n}{0}, \binom{n}{1}, \binom{n}{2}, \binom{n}{3}, \binom{n}{4}, \binom{n}{5}, \dots, \binom{n}{n}$ respectively. If the mean of this data is 60, then its median is :
be $\mu$ and $\sigma$, respectively. If $\sigma - \mu = 2$, then $\sigma + \mu$ is equal to ________.