a(n) = least positive integer > a(n-1) and not equal to a(i)*a(j) for 1<=i<=j<=n.

Terms

a(0) =3a(1) =4a(2) =5a(3) =6a(4) =7a(5) =8a(6) =10a(7) =11a(8) =13a(9) =14a(10) =17a(11) =19a(12) =22a(13) =23a(14) =26a(15) =27a(16) =29a(17) =31a(18) =34a(19) =37a(20) =38a(21) =41a(22) =43a(23) =45a(24) =46a(25) =47a(26) =53a(27) =54a(28) =58a(29) =59