Numbers k such that 11*10^k - 1 is prime.

Terms

a(0) =1a(1) =9a(2) =11a(3) =17a(4) =22a(5) =29a(6) =36a(7) =37a(8) =52a(9) =166a(10) =448a(11) =2011a(12) =3489a(13) =4871a(14) =6982a(15) =10024a(16) =16974a(17) =33287a(18) =47364a(19) =58873a(20) =126160a(21) =234424a(22) =382881a(23) =524706