In Prolog********. How would I write this? New to using math in prolog.

1. Write the recursive Prolog predicate named myfun/2, where the first argument is the input of the function below, and the second argument is matched with the output of the function. Use the integer/1 predicate for error checking. f(n)=3,4,f(n1)+2f(n2),n=1n=2n3 For example, ?-myfun(3,R)