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

Terms

a(0) =2a(1) =4a(2) =5a(3) =7a(4) =8a(5) =9a(6) =11a(7) =13a(8) =14a(9) =15a(10) =17a(11) =19a(12) =21a(13) =23a(14) =25a(15) =26a(16) =29a(17) =31a(18) =33a(19) =35a(20) =39a(21) =41a(22) =43a(23) =45a(24) =49a(25) =50a(26) =53a(27) =55a(28) =56a(29) =59