#!/bin/sh

if [ $# -ne 1 ]; then
  echo "usage: square num" >&2
  exit 1
elif [ "$1" -lt 0 ]; then
  exit 0
fi

j=0

while [ $j -le "$1" ]; do
  js=`echo "$j * $j" | bc`
  echo $j $js
  j=`echo $j + 1 | bc`
done