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

Terms

a(0) =1a(1) =-2a(2) =2a(3) =-2a(4) =4a(5) =-10a(6) =22a(7) =-44a(8) =86a(9) =-170a(10) =340a(11) =-682a(12) =1366a(13) =-2732a(14) =5462a(15) =-10922a(16) =21844a(17) =-43690a(18) =87382a(19) =-174764a(20) =349526a(21) =-699050a(22) =1398100a(23) =-2796202a(24) =5592406a(25) =-11184812a(26) =22369622a(27) =-44739242a(28) =89478484a(29) =-178956970