Numbers k such that 4*10^k - 71 is prime.

Terms

a(0) =3a(1) =4a(2) =6a(3) =11a(4) =12a(5) =17a(6) =21a(7) =54a(8) =82a(9) =112a(10) =189a(11) =235a(12) =426a(13) =442a(14) =4897a(15) =12463a(16) =14383a(17) =18630a(18) =38669a(19) =95752a(20) =108238a(21) =179265