Numbers whose base-7 representation has the same number of 1's and 5's.

Terms

a(0) =0a(1) =2a(2) =3a(3) =4a(4) =6a(5) =12a(6) =14a(7) =16a(8) =17a(9) =18a(10) =20a(11) =21a(12) =23a(13) =24a(14) =25a(15) =27a(16) =28a(17) =30a(18) =31a(19) =32a(20) =34a(21) =36a(22) =42a(23) =44a(24) =45a(25) =46a(26) =48a(27) =54a(28) =68a(29) =75