factorial

Find the factorial of a number.

Similar: factorial, binomial, multinomial.

function factorial(n, k?)
// n: a number
// k: denominator factorial [0]

const xmath = require('extra-math');


xmath.factorial(5);
// → 120

xmath.factorial(6);
// → 720

xmath.factorial(7);
// → 5040

References

• alawatthe/MathLib factorial.ts
• Permutation: Wikipedia