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

Terms

a(0) =1a(1) =2a(2) =3a(3) =5a(4) =7a(5) =8a(6) =11a(7) =12a(8) =13a(9) =17a(10) =18a(11) =19a(12) =20a(13) =23a(14) =27a(15) =28a(16) =29a(17) =30a(18) =31a(19) =32a(20) =37a(21) =41a(22) =42a(23) =43a(24) =44a(25) =45a(26) =47a(27) =48a(28) =50a(29) =52