Near-repdigit semiprimes with 4 as repeated digit.

Terms

a(0) =445a(1) =446a(2) =447a(3) =454a(4) =4414a(5) =4442a(6) =4443a(7) =4449a(8) =4474a(9) =44441a(10) =44494a(11) =444441a(12) =444494a(13) =4444441a(14) =4444449a(15) =44444441a(16) =44444446a(17) =44444447a(18) =444444449a(19) =444444454a(20) =4444444441a(21) =4444444443a(22) =44444444443a(23) =44444444446a(24) =44444444449a(25) =444444444447