摘要Schnirelman’s density is an important concept of the set of natural numbers. In recent years, the efforts of approaching the well-known Goldbach conjecture by using the density method have obtained important achievements in virtue of the
10Ying Chun CAI Department of Mathematics, Shanghai University, Shanghai 200436. P. R. China.Chen's Theorem with Small Primes[J].Acta Mathematica Sinica,English Series,2002,18(3):597-604.
