For maximum no of records in leaf node-

Root can have a max of m child Thus at h=1 no of leaf nodes would be m

Each of internal node can have a maximum of 2*m-1 child thus for h=2 no of leaf nodes would be m*(2m-1)

For h=3 max no of leaf nodes=m*((2m-1)^2)

So for a general expression max no of leaf nodes =m *((2m-1)^h-1)

Please correct me if i am wrong...