Smallest nonempty set S containing prime divisors of 6k+1 for each k in S.

Terms

a(0) =5a(1) =7a(2) =11a(3) =13a(4) =17a(5) =19a(6) =23a(7) =29a(8) =31a(9) =37a(10) =43a(11) =59a(12) =61a(13) =67a(14) =71a(15) =79a(16) =103a(17) =139a(18) =167a(19) =223a(20) =367a(21) =547a(22) =619a(23) =743a(24) =2203a(25) =13219