Primes formed by concatenating k, k and 3 for k >= 1.

Terms

a(0) =113a(1) =223a(2) =443a(3) =773a(4) =883a(5) =10103a(6) =11113a(7) =14143a(8) =25253a(9) =26263a(10) =28283a(11) =32323a(12) =35353a(13) =41413a(14) =50503a(15) =61613a(16) =68683a(17) =71713a(18) =77773a(19) =80803a(20) =83833a(21) =85853a(22) =88883a(23) =97973a(24) =1001003a(25) =1011013a(26) =1101103a(27) =1131133a(28) =1161163a(29) =1181183