Numbers k such that (388*10^k - 1)/9 is prime.

Terms

a(0) =0a(1) =1a(2) =7a(3) =12a(4) =16a(5) =18a(6) =37a(7) =67a(8) =82a(9) =90a(10) =133a(11) =622a(12) =624a(13) =1464a(14) =1963a(15) =4741a(16) =4824a(17) =13861a(18) =18423a(19) =61374