Semiprimes with only semiprime digits, each appearing at least once.

Terms

a(0) =469a(1) =649a(2) =694a(3) =4469a(4) =4694a(5) =4699a(6) =4946a(7) =6499a(8) =6649a(9) =6694a(10) =9446a(11) =9466a(12) =9469a(13) =9946a(14) =44669a(15) =44966a(16) =44969a(17) =46469a(18) =46946a(19) =46969a(20) =46994a(21) =46999a(22) =49466a(23) =49649a(24) =49694a(25) =49699a(26) =49969a(27) =64469a(28) =64649a(29) =64669