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

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =6a(5) =8a(6) =9a(7) =10a(8) =12a(9) =13a(10) =14a(11) =16a(12) =18a(13) =20a(14) =21a(15) =22a(16) =24a(17) =28a(18) =30a(19) =32a(20) =33a(21) =34a(22) =36a(23) =37a(24) =40a(25) =42a(26) =44a(27) =45a(28) =46a(29) =48