Numbers k such that (109*10^k + 17)/9 is prime.

Terms

a(0) =2a(1) =3a(2) =9a(3) =23a(4) =27a(5) =32a(6) =50a(7) =80a(8) =107a(9) =140a(10) =992a(11) =1607a(12) =2975a(13) =4007a(14) =4605a(15) =12392a(16) =15159a(17) =16628a(18) =37419