a(n) = 2*A004001(n) - n, where A004001 is the Hofstadter-Conway $10000 sequence.

Terms

a(0) =1a(1) =0a(2) =1a(3) =0a(4) =1a(5) =2a(6) =1a(7) =0a(8) =1a(9) =2a(10) =3a(11) =2a(12) =3a(13) =2a(14) =1a(15) =0a(16) =1a(17) =2a(18) =3a(19) =4a(20) =3a(21) =4a(22) =5a(23) =4a(24) =5a(25) =4a(26) =3a(27) =4a(28) =3a(29) =2