Primes of the form prime(2k) followed by prime(k).

Terms

a(0) =73a(1) =197a(2) =7129a(3) =10141a(4) =15161a(5) =19379a(6) =271109a(7) =373157a(8) =593251a(9) =757331a(10) =983431a(11) =997433a(12) =1069463a(13) =1231547a(14) =1361599a(15) =1531661a(16) =1571683a(17) =1627727a(18) =1831811a(19) =2069911a(20) =2161967a(21) =2213977a(22) =24731093a(23) =25311103a(24) =26931193a(25) =27131213a(26) =27911237a(27) =28191259