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

Terms

a(0) =5a(1) =9a(2) =15a(3) =24a(4) =35a(5) =50a(6) =69a(7) =93a(8) =123a(9) =160a(10) =206a(11) =261a(12) =327a(13) =406a(14) =501a(15) =612a(16) =744a(17) =898a(18) =1078a(19) =1286a(20) =1527a(21) =1806a(22) =2125a(23) =2492a(24) =2913a(25) =3390a(26) =3936a(27) =4553a(28) =5250a(29) =6036