a(1) = 2; a(n+1) = a(n)-th nonprime, where nonprimes begin at 1.

Terms

a(0) =2a(1) =4a(2) =8a(3) =14a(4) =22a(5) =33a(6) =48a(7) =66a(8) =90a(9) =120a(10) =156a(11) =202a(12) =256a(13) =322a(14) =400a(15) =494a(16) =604a(17) =734a(18) =888a(19) =1067a(20) =1272a(21) =1512a(22) =1790a(23) =2107a(24) =2472a(25) =2890a(26) =3364a(27) =3903a(28) =4515a(29) =5207