| dnbconv | Probability mass function | 
| nbconv_params | Summary statistics | 
| nb_sum_exact | Furman's PMF | 
| nb_sum_moments | Method of moments | 
| nb_sum_saddlepoint | Saddlepoint approximation | 
| pnbconv | Cumulative distribution function | 
| qnbconv | Quantile function | 
| rnbconv | Random deviates |