How do I represent a multi-dimensional state using a neural network? I have a set of 15 unique playing cards from a deck of 52 playing cards. A given state is represented by the respective card values in the set of 15 cards, where the card value is a prime number associated with that card. For example, AH is represented by 3.

How should I represent a single state for the NN? Should it be a list of the 15 prime numbers representing the list of cards? I was hoping that I could represent a single state as the sum of each of all 15 prime numbers and then throw that sum through a sigmoid function. My concern, however, is that the NN will lose information if I reduce the dimension of the state to a single attribute (even if that attribute is unique to that state - the sum of n prime numbers is unique compared to the sum of any other n prime numbers).

How important is the dimensionality of each state for Deep Q Learning? I'd really appreciate even some general direction.
In my humble opinion, it seems like it is important to have them separated, if having a certain card can influence the result in some way that is not its prime value, instead of not only using the sum. But it depends on the game and its rules. For example:

If having 5 cards of hearts in the set of 15 cards makes you win the game, then if you only represent the state as the sum of the value of the cards, the DQN will never learn that it was not the whole 15 cards that caused you to win, but only a specific part of the set.