a(n) = 2n+1 if 2n+1 is prime else a(n) = least prime of the form (2n+1)(2n+3)...(2n+2k-1) + 2.

Terms

a(0) =3a(1) =5a(2) =7a(3) =101a(4) =11a(5) =13a(6) =257a(7) =17a(8) =19a(9) =9454727a(10) =23a(11) =677a(12) =801011a(13) =29a(14) =31a(15) =42737a(16) =1297a(17) =37a(18) =1601a(19) =41a(20) =43a(21) =5285387a(22) =47a(24) =148667a(25) =53a(26) =3137a(27) =56284059197a(28) =59a(29) =61a(31) =4357