Definition: The gamma function of n, written Γ(n), is ∫ 0∞ e-xxn-1dx. Recursively Γ(n+1) = nΓ(n). For non-negative integers Γ(n+1) = n!.
See also Stirling's formula.
Note: The gamma function is defined for all numbers whereas factorial is (strictly) only defined for non-negative integers.
MathWorld's gamma function
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Entry modified 17 December 2004.
HTML page formatted Tue Dec 6 16:16:32 2011.
Cite this as:
Paul E. Black, "gamma function", in Dictionary of Algorithms and Data Structures [online], Paul E. Black, ed., U.S. National Institute of Standards and Technology. 17 December 2004. (accessed TODAY) Available from: http://www.nist.gov/dads/HTML/gammaFunction.html