q-Factorial
The q-analog of the factorial (by analogy with the q-gamma function). For
an integer, the
-factorial is defined by
(Koepf 1998, p. 26). For
,
![[k]_q!=Gamma_q(k+1),](http://mathworld.wolfram.com/images/equations/q-Factorial/NumberedEquation1.gif) |
(4)
|
where
is the q-gamma function.
-factorials are implemented in the Wolfram Language as QFactorial[n, q].
The first few values are
REFERENCES:
Gasper, G. and Rahman, M. Basic Hypergeometric Series. Cambridge, England: Cambridge University Press, 1990.
Gosper, R. W. "Experiments and Discoveries in q-Trigonometry." In Symbolic Computation, Number Theory,Special Functions, Physics and Combinatorics. Proceedings of the Conference Held at the University of Florida, Gainesville, FL, November 11-13, 1999 (Ed. F. G. Garvan and M. E. H. Ismail). Dordrecht, Netherlands: Kluwer, pp. 79-105, 2001.
Koepf, W. Hypergeometric Summation: An Algorithmic Approach to Summation and Special Function Identities. Braunschweig, Germany: Vieweg, pp. 26 and 30, 1998.