If we have a deck of 48$48$ different cards and 4$4$ players each get 12$12$ cards, it is well known how to calculate the number of possible distributions: take fac(48) and divide 4 times by fac(12).$\frac{48!}{12!12!12!12!}$
In a german card came (Doppelkopf) there are 24$24$ different card types, but 2$2$ copies of each type, that is 48$48$ cards at all.
How many distributions when there are 4$4$ players? My first approach was to assume there are 48$48$ different cards, and then to divide by 2 and by 2 (... 24 times)$2^{24}$. But this underestimates the real number of distributions. Because: Say player 1 has both spade kings. This has been ruled out already by dividing by fak(12)$12!$. But if player 1 and player 2 both have a spade king, then we must divide by 2.
How to calculate the number of different distibutions?
Is there a closed formula as in the single card deck case?