<script>

                let n = prompt("enter number", "");
                let col,row;
                for (row = 1; row <= n; row++){
                    for (space = 1; space <= (n-row); space++){
                        document.write("&nbsp");
                    }

                    for(col = 1; col <= row; col++){
                    document.write (row + " ");
                    }
                    document.write("<br>");
                }

            </script>