Numbers k such that (85*10^k - 1)/3 is prime.

Terms

a(0) =1a(1) =2a(2) =5a(3) =9a(4) =64a(5) =69a(6) =118a(7) =377a(8) =409a(9) =616a(10) =959a(11) =1093a(12) =1726a(13) =3034a(14) =5929a(15) =8140a(16) =11197a(17) =15293a(18) =15381a(19) =27811a(20) =58091a(21) =63757a(22) =72025a(23) =83921a(24) =122585a(25) =139913a(26) =166297a(27) =256301