Random: unsigned int gsl_ran_pascal(const gsl_rng * r, double p, unsigned int k)
This function returns a random integer from the Pascal distribution. The
Pascal distribution is simply a negative binomial distribution with an
integer value of @math{n}.
for @c{$k \ge 0$}
@math{k >= 0}
Function: double gsl_ran_pascal_pdf(unsigned int k, double p, unsigned int n)
This function computes the probability @math{p(k)} of obtaining k
from a Pascal distribution with parameters p and
n, using the formula given above.