All natural numbers except 1, 2 and 4.

Terms

a(0) =3a(1) =5a(2) =6a(3) =7a(4) =8a(5) =9a(6) =10a(7) =11a(8) =12a(9) =13a(10) =14a(11) =15a(12) =16a(13) =17a(14) =18a(15) =19a(16) =20a(17) =21a(18) =22a(19) =23a(20) =24a(21) =25a(22) =26a(23) =27a(24) =28a(25) =29a(26) =30a(27) =31a(28) =32a(29) =33