Numbers written in an alternating binary-then-ternary base.

Terms

a(0) =0a(1) =1a(2) =10a(3) =11a(4) =20a(5) =21a(6) =100a(7) =101a(8) =110a(9) =111a(10) =120a(11) =121a(12) =1000a(13) =1001a(14) =1010a(15) =1011a(16) =1020a(17) =1021a(18) =1100a(19) =1101a(20) =1110a(21) =1111a(22) =1120a(23) =1121a(24) =2000a(25) =2001a(26) =2010a(27) =2011a(28) =2020a(29) =2021