Sum{k>=0, C(2^k-1,n-2*(2^k-1))}.

Terms

a(0) =1a(1) =0a(2) =1a(3) =1a(4) =0a(5) =0a(6) =1a(7) =3a(8) =3a(9) =1a(10) =0a(11) =0a(12) =0a(13) =0a(14) =1a(15) =7a(16) =21a(17) =35a(18) =35a(19) =21a(20) =7a(21) =1a(22) =0a(23) =0a(24) =0a(25) =0a(26) =0a(27) =0a(28) =0a(29) =0