a(n) = a(n-1)+a(n-2), n>1 ; a(0)=1, a(1)=-1.

Terms

a(0) =1a(1) =-1a(2) =0a(3) =-1a(4) =-1a(5) =-2a(6) =-3a(7) =-5a(8) =-8a(9) =-13a(10) =-21a(11) =-34a(12) =-55a(13) =-89a(14) =-144a(15) =-233a(16) =-377a(17) =-610a(18) =-987a(19) =-1597a(20) =-2584a(21) =-4181a(22) =-6765a(23) =-10946a(24) =-17711a(25) =-28657a(26) =-46368a(27) =-75025a(28) =-121393a(29) =-196418