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

Terms

a(0) =1a(1) =3a(2) =4a(3) =5a(4) =6a(5) =8a(6) =9a(7) =11a(8) =12a(9) =15a(10) =17a(11) =19a(12) =20a(13) =21a(14) =24a(15) =26a(16) =27a(17) =29a(18) =32a(19) =33a(20) =35a(21) =36a(22) =37a(23) =39a(24) =40a(25) =41a(26) =44a(27) =45a(28) =47a(29) =48