Numbers k such that (28*10^k + 701)/9 is prime.

Terms

a(0) =1a(1) =2a(2) =4a(3) =5a(4) =14a(5) =17a(6) =19a(7) =29a(8) =40a(9) =56a(10) =62a(11) =82a(12) =104a(13) =121a(14) =181a(15) =286a(16) =1307a(17) =2197a(18) =5764a(19) =37120a(20) =91715