Double primes: concatenation of the n-th prime with itself.

Terms

a(0) =22a(1) =33a(2) =55a(3) =77a(4) =1111a(5) =1313a(6) =1717a(7) =1919a(8) =2323a(9) =2929a(10) =3131a(11) =3737a(12) =4141a(13) =4343a(14) =4747a(15) =5353a(16) =5959a(17) =6161a(18) =6767a(19) =7171a(20) =7373a(21) =7979a(22) =8383a(23) =8989a(24) =9797a(25) =101101a(26) =103103a(27) =107107a(28) =109109a(29) =113113