6-almost primes with semiprime digits (digits 4, 6, 9 only).

Terms

a(0) =64a(1) =96a(2) =4644a(3) =4944a(4) =6664a(5) =6966a(6) =9464a(7) =9996a(8) =44464a(9) =44944a(10) =46496a(11) =46644a(12) =49644a(13) =49696a(14) =64449a(15) =64496a(16) =66444a(17) =66696a(18) =69444a(19) =69496a(20) =69966a(21) =94496a(22) =94644a(23) =94696a(24) =96496a(25) =96944a(26) =99666a(27) =99944a(28) =444496a(29) =444664