a(8n)=n, a(8n+4)=a(8n)+a(8n+8), a(4n+2)=a(4n)+a(4n+4), a(2n+1)=a(2n)+a(2n+2).

Terms

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