>>629 bash 4.3.42(3)

n=10000
eval "a=('' '' {2..$n})"
for i in ${a[@]}; do
 if [ ${a[$i]} ]; then
  echo $i
  for ((j=2*$i; j<=$n; j+=$i)); do
    unset a[$j]
  done
 fi
done

実行結果
$ bash 15_629_prime.sh
2

3

5

7

9941
9949
9967
9973