/*
 * Save as a NumberTriangle.java
 * Program for Print the Number Triangle
 */
package r4r.co.in;

import java.io.*;

public class NumberTriangle {

    public static void main(String[] args) throws IOException {

        BufferedReader Digit = new BufferedReader(new InputStreamReader(System.in));
        System.out.println("Enter the row of the Tringle :");
        String s1 = Digit.readLine();
        int n1 = Integer.parseInt(s1);

        //Code for Print the Number Triangle
        System.out.println("\n Here the Triangle:");

        for (int i = 1; i <= n1; i++) {
            for (int j = 1; j <= i; j++) {
                System.out.print("" + j);
            }
            System.out.print("\n");
        }
    }
}

 
Enter the row of the Tringle :
15
 Here the Triangle:
1
12
123
1234
12345
123456
1234567
12345678
123456789
12345678910
1234567891011
123456789101112
12345678910111213
1234567891011121314
123456789101112131415