Numbers k such that (238*10^k - 1)/3 is prime.

Terms

a(0) =0a(1) =2a(2) =3a(3) =4a(4) =6a(5) =10a(6) =12a(7) =38a(8) =40a(9) =47a(10) =59a(11) =76a(12) =131a(13) =154a(14) =227a(15) =404a(16) =762a(17) =782a(18) =987a(19) =993a(20) =3449a(21) =5692a(22) =10086a(23) =11630a(24) =15135a(25) =26384a(26) =28233a(27) =33179a(28) =48352a(29) =103210