Numbers whose base-6 representation has the same number of 0's and 4's.

Terms

a(0) =1a(1) =2a(2) =3a(3) =5a(4) =7a(5) =8a(6) =9a(7) =11a(8) =13a(9) =14a(10) =15a(11) =17a(12) =19a(13) =20a(14) =21a(15) =23a(16) =24a(17) =31a(18) =32a(19) =33a(20) =35a(21) =40a(22) =43a(23) =44a(24) =45a(25) =47a(26) =49a(27) =50a(28) =51a(29) =53