1
2      3
4      5     6
7      8     9      10
11  12   13     14     15



#include<stdio.h>
#include<conio.h>
#include<iostream.h>

void main()
{
    int n;
    clrscr();
    cout<<"Enter how many line you need to make pyramid = ";
    cin>>n;
    int k=1;
    for(int i=1;i<=n;i++)
    {
       for(int j=1;j<=i;j++)
       cout<<"    "<<k++;
       cout<<"\n";
    }


    getch();
}

///////////////////////////////////////////////////////////////////////////
Copy & paste this code in your TC & run, then you will get output.......
If you have any problem please comment below.........