Numbers k such that 9*10^k - 1 is prime.

Terms

a(0) =1a(1) =3a(2) =7a(3) =19a(4) =29a(5) =37a(6) =93a(7) =935a(8) =8415a(9) =9631a(10) =11143a(11) =41475a(12) =41917a(13) =48051a(14) =107663a(15) =212903a(16) =223871a(17) =260253a(18) =364521a(19) =383643a(20) =1009567a(21) =1762063