#include<stdio.h>
#include<conio.h>
#include<iostream.h>
void main()
{
int n;
clrscr();
cout<<"Enter how many number you sum = ";
cin>>n;
long int s=0;
for(int i=1;i<=n;i++)
s=s+(3*i-1)*(3*i+2)*(3*i+5);
cout<<"Summation = "<<s;
getch();
}
///////////////////////////////////////////////////////////////////////////
Copy & paste this code in your TC & run, then you will get output.......
If you have any problem please comment below.........