Numbers k such that (268*10^k - 1)/3 is prime.

Terms

a(0) =0a(1) =2a(2) =6a(3) =7a(4) =12a(5) =13a(6) =17a(7) =18a(8) =26a(9) =77a(10) =151a(11) =222a(12) =403a(13) =567a(14) =1107a(15) =7221a(16) =7722a(17) =8475a(18) =9729a(19) =17904a(20) =21404a(21) =30170a(22) =62523