There is a game in wich you roll a number of ten sided dice and look for matches, a match is when two or more dice turn up the same number, well I have this table:

Dice poolChance of getting one or more matches10,00%210,00%328,00%450,00%570,00%685,00%793,00%898,00%999,60%1099'9%

But I'm looking for the general formula that shows the chance of getting matches with n dice.