Numbers k such that (13*10^k + 197)/3 is prime.

Terms

a(0) =1a(1) =2a(2) =4a(3) =5a(4) =17a(5) =21a(6) =23a(7) =28a(8) =41a(9) =43a(10) =51a(11) =59a(12) =105a(13) =115a(14) =131a(15) =273a(16) =585a(17) =1519a(18) =2303a(19) =4791a(20) =4921a(21) =6019a(22) =7833a(23) =25711a(24) =27319a(25) =32497a(26) =37975a(27) =49381a(28) =87199