Primes of the concatenated form 1nn1 where n is an integer >=0.

Terms

a(0) =112121a(1) =113131a(2) =115151a(3) =119191a(4) =127271a(5) =131311a(6) =134341a(7) =136361a(8) =140401a(9) =142421a(10) =145451a(11) =149491a(12) =157571a(13) =158581a(14) =161611a(15) =169691a(16) =170701a(17) =172721a(18) =178781a(19) =182821a(20) =187871a(21) =190901a(22) =191911a(23) =196961a(24) =197971a(25) =1100010001a(26) =1100210021a(27) =1101710171