Numbers whose base-7 representation has the same number of 2's and 4's.

Terms

a(0) =0a(1) =1a(2) =3a(3) =5a(4) =6a(5) =7a(6) =8a(7) =10a(8) =12a(9) =13a(10) =18a(11) =21a(12) =22a(13) =24a(14) =26a(15) =27a(16) =30a(17) =35a(18) =36a(19) =38a(20) =40a(21) =41a(22) =42a(23) =43a(24) =45a(25) =47a(26) =48a(27) =49a(28) =50a(29) =52