if [[ $# -ne 1 ]]; then
  echo "usage: $0 <number>"
  echo "please provide exactly one numeric argument"
  exit 1
fi

if ! [[ "$1" =~ ^[0-9]+$ ]] || (("$1" < 1)); then
  echo "error: argument must be a positive integer"
  exit 1
fi

reset
for ((i = 2; i < "$(($1 + 1))"; i++)); do
  cowsay "$((($i - 1) * ($i - 1)))"
  sleep 1
  clear
done
cowsay -e oo -T U "$(($1 * $1))"