a(n) = - 2*a(n-1) - 8*a(n-3), a(0) = 1, a(1) = 1, a(2) = -2.

Terms

a(0) =1a(1) =1a(2) =-2a(3) =-4a(4) =0a(5) =16a(6) =0a(7) =0a(8) =-128a(9) =256a(10) =-512a(11) =2048a(12) =-6144a(13) =16384a(14) =-49152a(15) =147456a(16) =-425984a(17) =1245184a(18) =-3670016a(19) =10747904a(20) =-31457280a(21) =92274688a(22) =-270532608a(23) =792723456a(24) =-2323644416a(25) =6811549696a(26) =-19964887040a(27) =58518929408a(28) =-171530256384a(29) =502779609088