Recursion-3

Q1 - Given a number n, print the following pattern without using any loop.
n, n-5, n-10, ..., 0, 5, 10, ..., n-5, n


Input  = 16
Expected Output 16, 11, 6, 1, -4, 1, 6, 11, 16
     
import java.util.*;
import java.util.Scanner;
public class Test{
        public static void main(String[] args){
                Scanner scn = new Scanner(System.in);
                System.out.println("Enter the number n: ");
                int n = scn.nextInt();
                rec(n, n, true);
        }
        public static void rec(int n, int m, boolean flag) {
                System.out.print(m + " ");
                // If we are moving back towards n and we have reached there, then we are done
                if (flag == false && n == m)
                        return;
 
                // If we are moving towards 0 or negative.
                if (flag) {
                        // If m is greater, then 5, recur with true flag
                        if (m - 5 > 0)
                                rec(n, m - 5, true);
 
                        else // recur with false flag
                                rec(n, m - 5, false);
                }
 
                else // If flag is false.
                        rec(n, m + 5, false);
        }
}


Q2 - Find m-th summation of first n natural numbers where m-th summation of first n natural
numbers is defined as following:
If m > 1: SUM(n, m) = SUM(SUM(n, m - 1), 1)
Else :SUM(n, 1) = Sum of first n natural numbers.
import java.util.*;
import java.util.Scanner;
public class Test{
        public static void main(String[] args){
                Scanner scn = new Scanner(System.in);
                System.out.println("Enter the number n and m: ");
                int n = scn.nextInt();
                int m = scn.nextInt();
                System.out.println(rec(n, m));
        }
        public static int rec(int n, int m) {
                if (m == 1)
                        return sumofn(n);
 
                int sum = rec(n, m - 1);
                return sumofn(sum);
        }
        public static int sumofn(int n){
                int ans = 0;
                if(n == 1){
                        ans++;
                        return ans;
                }
                ans += n + sumofn(n-1);
                return ans;
        }
}