Numbers k such that (71*10^k - 287)/9 is prime.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =26a(5) =28a(6) =43a(7) =70a(8) =92a(9) =128a(10) =331a(11) =364a(12) =478a(13) =532a(14) =689a(15) =778a(16) =895a(17) =1210a(18) =5081a(19) =7855a(20) =17852a(21) =20864a(22) =42598a(23) =56858a(24) =120703a(25) =173854