7.12. 1^2.2^2+ 2^2.3^2+ 3^2.4^2+.............upto n'th term.

#include<stdio.h> 
#include<conio.h>
void main ()
{
int i,n, sum=0;
clrscr ();
printf("How many number: ");
scanf("%d", &n);
for (i=1; i<=n, i++)
sum=sum+i*i*(i+1)*(i+1);
printf("Sum= %d", sum); 
getch(); 
}