pub fn binom<F: Float>(n: F, k: F) -> FExpand description
C(n, k), the binomial coefficient. Whole n and k from 0 multiply out exactly while the result times |n| + k is a whole number the type holds, and a negative whole n gives (-1)^k C(k - n - 1, k). Other n with a whole k from 0 to 64 multiply out n(n - 1)…(n - k + 1)/k!, within 2k ulps. Other real arguments take Γ(n + 1)/(Γ(k + 1) Γ(n - k + 1)) in double words, within 4 ulps in tests against mpmath, for large n and negative arguments too.