 The identity formula_28 can be used (or, yielding the same result, analytic continuation can be used) to uniquely extend the integral formulation for formula_16 to a meromorphic function defined for all complex numbers , except integers less than or equal to zero.It is this extended version that is commonly referred to as the gamma function.When seeking to approximate formula_30 for a complex number formula_31, it is effective to first compute formula_32 for some large integer formula_33.