STIRLING'S FORMULA

[Stir.ling's formula] n [James Stirling d. 1770 Scot. mathematician] (1926): a formula that approximates the value of the factorial of a very large number n and that consists of the product of three terms of which the first consists of n raised to the exponent n, the second consists of the transcendental number e raised to the negative exponent n, and the third consists of the square root of the product of 2n times the transcendental number pi