Primes that contain digits 4 and 9 only.

Terms

a(0) =449a(1) =499a(2) =4999a(3) =9949a(4) =44449a(5) =49499a(6) =49999a(7) =94949a(8) =94999a(9) =444449a(10) =994949a(11) =999499a(12) =4444949a(13) =4449449a(14) =4944949a(15) =4949449a(16) =4999949a(17) =4999999a(18) =9444949a(19) =9494999a(20) =9944449a(21) =9994499a(22) =44444999a(23) =44499449a(24) =44944499a(25) =44994949a(26) =49444949a(27) =49444999a(28) =49494499