A nonsense sequence.

Terms

a(0) =-1a(1) =1a(2) =-1a(3) =2a(4) =-2a(5) =4a(6) =-4a(7) =7a(8) =-7a(9) =12a(10) =-12a(11) =22a(12) =-21a(13) =39a(14) =-39a(15) =68a(16) =-70a(17) =119a(18) =-127a(19) =210a(20) =-229a(21) =369a(22) =-413a(23) =649a(24) =-742a(25) =1143a(26) =-1334a(27) =2017a(28) =-2393a(29) =3561