/*

   stirling - Numerator program for evaluating Stirling's formula.

              Stirling's formula gives an approximation for the factorial
              of a number (i.e.  Stirling approximation for 3! is
              5.998326524)
	      
*/

get n
sqrt (2 * n * PI) * ((n / E) ^ n) * (1 + 1 / (12 * n))