Return double factorial
n(n-2)...(5)(3)(1), n>0, odd
n!! = n(n-2)...(6)(4)(2), n>0, even
1 , n = -1, or n = 0
6!! = (6)(4)(2) = 48
Neither n = -1, nor n = 0 are tested.
Sort a list of complex numbers based on far they are from the origin.
Which doors are open?
5 Prime Numbers
Bridge and Torch Problem - Minimum time
Hexagonal numbers on a spiral matrix
Bridge and Torch Problem - Length of Unique Time List
Go back n times
Choose a web site to get translated content where available and see local events and offers. Based on your location, we recommend that you select: .
You can also select a web site from the following list:
Select the China site (in Chinese or English) for best site performance. Other MathWorks country sites are not optimized for visits from your location.
Contact your local office