A class of integral approximations for the factorial function
We introduce Stirlings formula in a more general class of approximation formulas to extend the integral representation of Liu [Z. Liu, A new version of the Stirling formula, Tamsui Oxf. J. Math. Sci. 23 (4) (2007) 389392]. Finally, an accurate approximation for the factorial function is established.
stirlings formula gamma function burnsides formula numeric series improper integrals rate of convergence