a(n+1) = a(n) - a(floor(n/2)), with a(0)=0, a(1)=1.

Terms

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