a(n) = Sum_{k=0..n} (-1)^k*floor(phi^k), where phi is the golden ratio (A001622).

Terms

a(0) =1a(1) =0a(2) =2a(3) =-2a(4) =4a(5) =-7a(6) =10a(7) =-19a(8) =27a(9) =-49a(10) =73a(11) =-126a(12) =195a(13) =-326a(14) =516a(15) =-848a(16) =1358a(17) =-2213a(18) =3564a(19) =-5785a(20) =9341a(21) =-15135a(22) =24467a(23) =-39612a(24) =64069a(25) =-103692a(26) =167750a(27) =-271454a(28) =439192a(29) =-710659