a(n) = -5*a(n-1)-4*a(n-2) with n>1, a(0)=0, a(1)=1.

Terms

a(0) =0a(1) =1a(2) =-5a(3) =21a(4) =-85a(5) =341a(6) =-1365a(7) =5461a(8) =-21845a(9) =87381a(10) =-349525a(11) =1398101a(12) =-5592405a(13) =22369621a(14) =-89478485a(15) =357913941a(16) =-1431655765a(17) =5726623061a(18) =-22906492245a(19) =91625968981a(20) =-366503875925