G.f.: Product_{k>0} (1-x^(2k-1))/(1-x^(2k)).

Terms

a(0) =1a(1) =-1a(2) =1a(3) =-2a(4) =3a(5) =-4a(6) =5a(7) =-7a(8) =10a(9) =-13a(10) =16a(11) =-21a(12) =28a(13) =-35a(14) =43a(15) =-55a(16) =70a(17) =-86a(18) =105a(19) =-130a(20) =161a(21) =-196a(22) =236a(23) =-287a(24) =350a(25) =-420a(26) =501a(27) =-602a(28) =722a(29) =-858