C :

#include<stdio.h>
#include<string.h>
int main(){
    int i;
    int a[15]={1,2,6,3,7,10,4,8,11,13,5,9,12,14,15};
    for(i=0;i<15;i++){
        if(a[i]==1) printf("%d\n",a[i]);
        else if(a[i]==2) printf("%d ",a[i]);
        else if(a[i]==6) printf("%d\n",a[i]);
        else if(a[i]==3||a[i]==7) printf("%d ",a[i]);
        else if(a[i]==10) printf("%d\n",a[i]);
        else if(a[i]==4||a[i]==8||a[i]==11) printf("%d ",a[i]);
        else if(a[i]==13) printf("%d\n",a[i]);
        else if(a[i]==5||a[i]==9||a[i]==12||a[i]==14) printf("%d ",a[i]);
        else if(a[i]==15) printf("%d",a[i]);
    }



return 0;
}

C++ :

#include<iostream>
using namespace std;

int main(){
	for(int i=1;i<=5;i++){
		switch(i){
		case 1:
			cout<<i<<endl;
			continue;
		case 2:
			cout<<i<<" "<<i+4<<endl;
			continue;
		case 3:
			cout<<i<<" "<<i+4<<" "<<i+7<<endl;
			continue;
		case 4:
			cout<<i<<" "<<i+4<<" "<<i+7<<" "<<i+9<<endl;
			continue;
		case 5:
			cout<<i<<" "<<i+4<<" "<<i+7<<" "<<i+9<<" "<<i+10<<endl;
			continue;
		}
	}	
	return 0;
}

Java :

public class Main 
    {
            public static void main(String[] args)
            {  
              for(int i=1;i<=5;i++) {
                 int a=i;
                int b= 4;
                for(int j =0;j<i;j++) {
                
                  System.out.print(a);
                  if(j+1<i)
                   System.out.print(" "); 
                  a=a+b;
                  b--;
                }
                System.out.println();
              }
            }
}