main()
{
 int a,i;
 clrscr();
 printf("\nEnter an integer: ");
 scanf("%d",&a);
 if(a<20)
 {
  printf("\nThe square of integers from %d till 20 is: \n",a);
  for(i=a;i<=20;i++)
   printf("%d ",i*i);
 }
 else
  printf("\nThe number you entered is greater than 20.");
}