Numbers whose base-10 representation has the same number of 0's and 1's.

Terms

a(0) =2a(1) =3a(2) =4a(3) =5a(4) =6a(5) =7a(6) =8a(7) =9a(8) =10a(9) =22a(10) =23a(11) =24a(12) =25a(13) =26a(14) =27a(15) =28a(16) =29a(17) =32a(18) =33a(19) =34a(20) =35a(21) =36a(22) =37a(23) =38a(24) =39a(25) =42a(26) =43a(27) =44a(28) =45a(29) =46