Complex sentence: The formula calculates the summation of the combinations without repetition for r slimes multiplied by the permutations with repetition for r slimes, or the total number of positions which can be achieved for every number of slimes possible without ending the game.
Split into simpler sentences: The formula calculates the summation of the combinations without repetition for r slimes multiplied by the permutations with repetition for r slimes. Or the total number of positions which can be achieved for every number of slimes possible without ending the game.