Fibonacci Series

#!/bin/bash

a=0
b=1
echo -n "Enter the number of terms: "
read n

if [ $n -le 0 ]; then
    echo "Error in input"
    exit 0
fi

if [ $n -ge 1 ]; then
    echo -n $a " "          #-n used for printing on the same line
fi
if [ $n -ge 2 ]; then
    echo -n $b " "
fi
for(( i=2; i<n; i++ )){     #i=2 because 2 numbers have already been printed
    c=$((a+b))      #equivalent to let c=a+b
    echo -n $c " "
    a=$b
    b=$c
}
echo ""