Your challenge, should you chose to accept it, is to code-golf a function that returns true or false (or some similar meaningful representation of yes and no) if a number meets the following criteria:
- The integer itself is a prime number OR
- Either of its neighbor integers are prime
For example:
An input of 7
would return True.
An input of 8
would also return True.
An input of 15
would return False. (Neither 14, 15, or 16 are prime)
The input must be able to return correctly for numbers between 2^0 and 2^20 inclusive, so there's no need to worry about sign issues or integer overflows.