Numbers whose base-4 representation contains exactly four 1's and two 3's.

Terms

a(0) =1375a(1) =1399a(2) =1405a(3) =1495a(4) =1501a(5) =1525a(6) =1879a(7) =1885a(8) =1909a(9) =2005a(10) =3415a(11) =3421a(12) =3445a(13) =3541a(14) =3925a(15) =4447a(16) =4471a(17) =4477a(18) =4567a(19) =4573a(20) =4597a(21) =4951a(22) =4957a(23) =4981a(24) =5077a(25) =5215a(26) =5239a(27) =5245a(28) =5335a(29) =5341