How many way can we write the integer n as the sum of non nigative integer such that the largest number of the k non-negative integers is d. The condition is the largest number in all k non-negative must be dd. For example, I can write 10 as 3+3+2+1+1, 3+3+2+1+1 and 3+2+2+2+1, 3+2+2+2+1 if k=5 and d=3.