Gamma[a, z] \[Proportional] (Sqrt[2 Pi] a^(a - 1/2) (1 + 1/(12 a) + 1/(288 a^2) + O[1/a^3]))/E^a - (z^a/(E^z a)) (1 + z/a + ((z - 1) z)/a^2 + O[1/a^3]) /; (Abs[a] -> Infinity)

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2007-05-02