a(n+4) = a(n+1) - a(n), a(0) = 1, a(1) = -4, a(2) = 0, a(3) = 1.

Terms

a(0) =1a(1) =-4a(2) =0a(3) =1a(4) =-5a(5) =4a(6) =1a(7) =-6a(8) =9a(9) =-3a(10) =-7a(11) =15a(12) =-12a(13) =-4a(14) =22a(15) =-27a(16) =8a(17) =26a(18) =-49a(19) =35a(20) =18a(21) =-75a(22) =84a(23) =-17a(24) =-93a(25) =159a(26) =-101a(27) =-76a(28) =252a(29) =-260