A generalization of a waiting time problem
Beih S. El-Desouky, S Hussen · Advances in Applied Probability · 1990
An urn contains m types of balls of unequal numbers. Let n i be the number of balls of type i, i = 1, 2, …, m. Balls are drawn with replacement until first duplication. In the case of finite memory of order k, the distribution of Y m,k, the number of drawings required, is discussed. Special cases are obtained.