#!/bin/bash
echo -n "Enter Number :"
read nb

for (( i=1 ; $i <= $nb ; i=$(($i+1)) )); do
    for (( j=1 ; $j <= $(($nb-$i)) ; j=$(($j+1)) )); do
	echo -n "  "
    done
    for (( j=$(($(($nb-i))+1)) ; $j <= $nb ; j=$(($j+2)) )); do
	if [ $j -lt 10 ]
	then
	    echo -n " "
	fi
	echo -n "$j  "
    done
    echo
done
for (( i=$(($nb-1)) ; $i >= 1 ; i=$(($i-1)) )); do
    for (( j=1 ; $j <= $(($nb-$i)) ; j=$(($j+1)) )); do
	echo -n "  "
    done
    for (( j=$(($(($nb-i))+1)) ; $j <= $nb ; j=$(($j+2)) )); do
	if [ $j -lt 10 ]
	then
	    echo -n " "
	fi
	echo -n "$j  "
    done
    echo
done