Let for the 9th term in the binomial expansion of $(3 + 6x)^n$, in the increasing powers of $6x$, to be the greatest for $x = 3/2$, the least value of $n$ is $n_0$. If $k$ is the ratio of the coefficient of $x^6$ to the coefficient of $x^3$, then $k + n_0$ is equal to