简介:LetpdenoteaprimeandP2denoteanalmostprimewithatmosttwoprimefactors.Theauthorprovesthatforsuffcientlylargex,sumfromp≤xp+2=P21>(1.13Cx)/(log~2x),wheretheconstant1.13constitutesanimprovementofthepreviousresult1.104duetoJ.Wu.
A Remark on Chen's Theorem (Ⅱ)