ANSWER IN C++

Write a recursive function that calculates the number of combinations of X items that can be made from Y items by using the following formula:

Combinations (Y, X) =

Y if X = 1

1 if X = Y

(Combinations( Y-1, X-1) + 3* Combinations ( Y-1, X)) if Y > X > 1

Write a driver to print out the value for Combinations (5, 4) and Combinations (7, 5).