Duplicate of A023761.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =5a(5) =6a(6) =10a(7) =11a(8) =12a(9) =15a(10) =16a(11) =17a(12) =18a(13) =20a(14) =21a(15) =22a(16) =23a(17) =24a(18) =25a(19) =30a(20) =31a(21) =50a(22) =55a(23) =56a(24) =60a(25) =61a(26) =62a(27) =75a(28) =80a(29) =81