Chen Jingrun

Chen Jingrun (1933 - 1996) Chinese mathematician, best known for his theorem “on the representation of a large even integer as the sum of a prime and the product of at most two primes” (Chen’s theorem). In connection with this theorem, the Chen primes are named after him. Chen also worked on the twin prime conjecture, Goldbach’s conjecture, Legendre’s conjecture and Waring’s problem.

In 1999, China issued an 80-yuan postage stamp with a silhouette of Chen and the inequality

$$P_x(1,2)\ge \frac{0.67x{C}_x}{{(\log x)}^2}.$$