Q. Print a Sum of first n even number ?

THE OUTPUT WOULD BE

#include<iostream.h>
#include<conio.h>
class A
{ int a,n,i;
public:
void B()
{ cout<<"Enter n:";
 cin>>n;
}
void C();
};
void A::C()
{       a=0;
cout<<"\nSum of first "<<n<<" even no. is= ";
for(i=1;i<=n;i++)
a=a+i*2;
cout<<a;
}
void main()
{ clrscr();
A obj;
obj.B();
obj.C();
getch();
}