#!/bin/bash
LIMIT=20 # Superior limit
echo "Print the numbers between 1 and 20 (with the exclusion of the numbers 4 and 13)."
a=0
while [ $a -lt "$LIMIT" ]
do
a=$(($a+1))
# a=$[$a+1] # Another possible way to compute mathematical operations
if [ "$a" -eq 4 ] || [ "$a" -eq 13 ] # Exclusion of 4 and 13 numbers
then
continue # Skip the rest of this cycle
fi
echo -n "$a "
done
echo # Print new line
exit 0