Primes formed by concatenating n with n+1.

Terms

a(0) =23a(1) =67a(2) =89a(3) =1213a(4) =3637a(5) =4243a(6) =5051a(7) =5657a(8) =6263a(9) =6869a(10) =7879a(11) =8081a(12) =9091a(13) =9293a(14) =9697a(15) =102103a(16) =108109a(17) =120121a(18) =126127a(19) =138139a(20) =150151a(21) =156157a(22) =180181a(23) =186187a(24) =188189a(25) =192193a(26) =200201a(27) =216217a(28) =242243a(29) =246247