Probability of exactly n default events Xiaofong Ma, "Numerical Methods for the Valuation of Synthetic Collateralized Debt Obligations", PhD Thesis, Graduate Department of Computer Science, University of Toronto, 2007 http://www.cs.toronto.edu/pub/reports/na/ma-07-phd.pdf (formula 2.1)
Loss distribution with Monte Carlo simulation
Loss distribution for varying volumes and probabilities of default via Monte Carlo simulation of independent default events.