a(1) = 5; a(n+1) = a(n)-th nonprime, where nonprimes begin at 4.

Terms

a(0) =5a(1) =10a(2) =18a(3) =28a(4) =42a(5) =60a(6) =84a(7) =115a(8) =152a(9) =198a(10) =253a(11) =320a(12) =399a(13) =494a(14) =605a(15) =736a(16) =891a(17) =1072a(18) =1280a(19) =1521a(20) =1800a(21) =2120a(22) =2488a(23) =2910a(24) =3387a(25) =3934a(26) =4552a(27) =5250a(28) =6038a(29) =6929