Numbers k such that 5*10^k - 7 is prime.

Terms

a(0) =1a(1) =3a(2) =4a(3) =8a(4) =14a(5) =16a(6) =24a(7) =61a(8) =80a(9) =87a(10) =104a(11) =108a(12) =144a(13) =2157a(14) =3325a(15) =4122a(16) =20718a(17) =51163a(18) =140744