a(0) = 0, a(1) = 1, a(2) = 3, a(3) = 2; thereafter a(n) = -4*a(n-4).

Terms

a(0) =0a(1) =1a(2) =3a(3) =2a(4) =0a(5) =-4a(6) =-12a(7) =-8a(8) =0a(9) =16a(10) =48a(11) =32a(12) =0a(13) =-64a(14) =-192a(15) =-128a(16) =0a(17) =256a(18) =768a(19) =512a(20) =0a(21) =-1024a(22) =-3072a(23) =-2048a(24) =0a(25) =4096a(26) =12288a(27) =8192a(28) =0a(29) =-16384