Factorial2

Factorial2(n)

n!!

returns the double factorial number of the integer n as n*(n-2)*(n-4)....

See

• Wikipedia - Double Factorial

Examples

>> Factorial2(3)
3

>> Factorial2(9)
945

>> Factorial2(10)
3840

Implementation status

• ✅ - full supported

Github

• Implementation of Factorial2