a(n) = (-3)^(n-1)*a(n-1) + a(n-2).A280222a(n) = (-3)^(n-1)*a(n-1) + a(n-2).Terms a(0) =0a(1) =1a(2) =-3a(3) =-26a(4) =699a(5) =56593a(6) =-13751400a(7) =-10024714007External referencesoeis: A280222