  In this paper, we first determine the optimal sets of $n$-means and the $n$th
quantization errors for all $1\leq n\leq 6$ for two nonuniform discrete
distributions with support the set $\{1, 2, 3, 4, 5, 6\}$. Then, for a
probability distribution $P$ with support $\{\frac 1n : n\in \mathbb N\}$
associated with a mass function $f$, given by $f(x)=\frac 1 {2^k}$ if $x=\frac
1 k$ for $k\in \mathbb N$, and zero otherwise, we determine the optimal sets of
$n$-means and the $n$th quantization errors for all positive integers up to
$n=300$. Further, for a probability distribution $P$ with support the set
$\mathbb N$ of natural number associated with a mass function $f$, given by
$f(x)=\frac 1 {2^k}$ if $x=k$ for $k\in \mathbb N$, and zero otherwise, we
determine the optimal sets of $n$-means and the $n$th quantization errors for
all positive integers $n$. At last we discuss for a discrete distribution, if
the optimal sets are given, how to obtain the probability distributions.

Probability;Combinatorics