Numbers k such that (22*10^k + 257)/9 is prime.

Terms

a(0) =1a(1) =3a(2) =4a(3) =6a(4) =22a(5) =31a(6) =201a(7) =265a(8) =340a(9) =388a(10) =396a(11) =561a(12) =1224a(13) =2841a(14) =3234a(15) =3538a(16) =8473a(17) =12061a(18) =29347a(19) =62926a(20) =146029