a(n) = a(n-1) - 16*a(n-2), a(0)=1, a(1)=4.

Terms

a(0) =1a(1) =4a(2) =-12a(3) =-76a(4) =116a(5) =1332a(6) =-524a(7) =-21836a(8) =-13452a(9) =335924a(10) =551156a(11) =-4823628a(12) =-13642124a(13) =63535924a(14) =281809908a(15) =-734764876a(16) =-5243723404a(17) =6512514612a(18) =90412089076a(19) =-13788144716