1) Class of prime number
Found on
https://www.crosswordclues.com/clue/twin-prime
A twin prime is a prime number that has a prime gap of two, in other words, differs from another prime number by two, for example the twin prime pair (41, 43). Sometimes the term twin prime is used for a pair of twin primes; an alternative name for this is prime twin or prime pair. Twin primes appear despite the general tendency of gaps between ad...
Found on
http://en.wikipedia.org/wiki/Twin_prime
No exact match found.
