Chen prime

Etymology
Named after Chinese mathematician, who proved in 1966 that there are infinitely many such numbers.

Noun

 * 1)  Any prime number p such that p+2 is either a semiprime or another prime.
 * 2) * 2013, Laura Hemphill, Buying In, Haughton Mifflin Harcourt (New Harvest), page 278,
 * She tried counting Chen primes. 2, 3, 5... 7, 11... 13... 17... She couldn't concentrate.