$34$ is quite an interesting number. It's the product of 2 different prime numbers: $2$ and $17$. Also, $34-1$ and $34+1$ also the products of 2 different prime numbers, which are $(3)$$(11)$ and $(5)$$(7)$ respectively.
We have a definition:
Definition: A positive integer n is called special if each of n, n-1 and n+1 is the product of 2 distinct prime numbers.
Question: Is there any special number beside $34$?
Note: I have figured out that if a number is special, then it must be even, but I don't khow what to do next.