a(n) = least positive integer < a(n-1) and not a(i)*a(j)-2 for 1<=i<j<=n.

Terms

a(0) =2a(1) =3a(2) =5a(3) =6a(4) =7a(5) =9a(6) =11a(7) =14a(8) =15a(9) =17a(10) =18a(11) =21a(12) =22a(13) =23a(14) =24a(15) =27a(16) =29a(17) =30a(18) =35a(19) =36a(20) =37a(21) =38a(22) =39a(23) =41a(24) =45a(25) =47a(26) =48a(27) =50a(28) =51a(29) =54