how-we-can-calclate-triple-factorial-

Question Number 96749 by student work last updated on 04/Jun/20

how we can calclate triple factorial ?

Answered by Rio Michael last updated on 04/Jun/20

The tripple factorial is defined as

n!!! = n (n - 3) (n - 6) \dots 3, n (n - 3) (n - 6) \dots 4 * 1

or n (n - 3) (n - 6) \dots 5 * 2 depending on the numbers congruency

so n!^{(a)} should be defined as the product of numbers congruent to n (\mod a)

as examples :

8 (\mod 3) \equiv 5 (\mod 3) \equiv 2 (\mod 3)

n!^{(a)} = n (n - a) (n - 2 a) \dots (m + 2 a) (m + a) m, where m is

the smallest possible number allowed by the factorial .