#!/bin/bash 
 factorial () 
 { 
 local num=$1; 
 if [ $num = 0 ]; then 
  echo 1 
 return ; 
 fi; 
 echo $(( $num * $(factorial $(( $num - 1 )) ) )) 
 } 
 for ((n = 0; n <= 16; n++)) 
 do 
  echo "$n! = " $(factorial $(($n))) 
 done