double factorial
The double factorial of a positive integer is the product of the positive integers less than or equal to that have the same parity as , that is,
where denotes if is an odd number and if is an even number.
For example,
Note that is not the same as .
Observe that and .
Title | double factorial |
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Canonical name | DoubleFactorial |
Date of creation | 2013-03-22 12:24:54 |
Last modified on | 2013-03-22 12:24:54 |
Owner | drini (3) |
Last modified by | drini (3) |
Numerical id | 9 |
Author | drini (3) |
Entry type | Definition |
Classification | msc 05A10 |