How do you express the product of $5*8*11*14$ $*$ $...$ in terms of factorials that are functions of $n$, where $n$ stands for the number of terms in the product? Notice that the terms of the product form an arithmetic sequence, in which the $i$th term of the sequence is $3i+2$.
For $n=1$ the product is $5$.
For $n=2$ the product is $5*8$.
For $n=3$ the product is $5*8*11$.
For $n=4$ the product is $5*8*11*14$.
And so on...
According to OEIS, the nth term of the sequence of products $5\times 8 \times 11...$ are one half of the triple factorial numbers.
For more information on multifactorials, you may want to check out this Wiki section.