Integers k such that 10^k - 27 is prime.

Terms

a(0) =2a(1) =4a(2) =7a(3) =14a(4) =20a(5) =22a(6) =29a(7) =31a(8) =40a(9) =80a(10) =85a(11) =224a(12) =767a(13) =952a(14) =3592a(15) =4016a(16) =4187a(17) =9239a(18) =17684a(19) =20716a(20) =30791