a(n) = least positive integer > a(n-1) and not a(i)*a(j)-1 for 1<=i<j<=n, with initial terms 3,4.

Terms

a(0) =3a(1) =4a(2) =5a(3) =6a(4) =7a(5) =8a(6) =9a(7) =10a(8) =12a(9) =13a(10) =15a(11) =16a(12) =18a(13) =21a(14) =22a(15) =24a(16) =25a(17) =28a(18) =30a(19) =32a(20) =33a(21) =36a(22) =37a(23) =40a(24) =42a(25) =43a(26) =45a(27) =46a(28) =48a(29) =50