Shell Script to accept a number n from user and display the squares of all numbers from 1 to n

Code:
echo -n "Enter the number : "
read n
c=1
a=1
while test $c -le $n
do
        let a=$c*$c
        echo "$c square = $a"
        let c=c+1
done


Output:
[ty2011330@localhost ~]$ sh j09.sh
Enter the number : 5
1 square = 1
2 square = 4
3 square = 9
4 square = 16
5 square = 25