Numbers k such that 7^k + 2 is semiprime.

Terms

a(0) =1a(1) =2a(2) =6a(3) =9a(4) =12a(5) =14a(6) =26a(7) =33a(8) =44a(9) =54a(10) =126a(11) =141a(12) =830a(13) =2436a(14) =3534a(15) =3846a(16) =4152a(17) =4460a(18) =4974a(19) =13160a(20) =13200a(21) =13832a(22) =21996a(23) =28065