Fibonacci series using recursive function in UNIX

Using Recursive function:
#!/bin/bash
if [ $# -eq 1 ]
then
    Num=$1
else
    echo -n "Enter a Number : "
    read Num
fi

#####################################################################
#                      Define Functions Here                        #
#####################################################################

Fibonacci()
{

case $1 in
 0|1) printf "$1 " ;;
 *) echo -n "$(( $(Fibonacci $(($1-2)))+$(Fibonacci $(($1-1))) )) ";;
esac

#$(( )) construct is used instead of expr command for doing addition.
#$( ) constrict is used instead of back ticks.

}

#####################################################################
#                      Main Script Starts Here                      #
#####################################################################

echo "The Fibonacci sequence for the number $Num is : "

for (( i=0; i<=$Num; i++ ))
do
  Fibonacci $i                     #Calling function Fibonacci
done

echo

Output:
Enter a Number :20
The Fibonacci sequence for the number 20 is :
0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181 6765