Naor's distribution is the discrete probability distribution which arises from the following model;
Assume an urn contains n balls of which one is red and the remainder is white.
Sampling with the replacement of a white ball (if drawn) by the red ball continues until the red ball is drawn. Then the probability distribution of the needed number of draws,
Y, is
after n - 1 draws urn contains only the red balls and so no more than n draws are needed.