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

Terms

a(0) =3a(1) =-1a(2) =-1a(3) =8a(4) =-9a(5) =-1a(6) =26a(7) =-43a(8) =15a(9) =80a(10) =-181a(11) =131a(12) =210a(13) =-703a(14) =755a(15) =368a(16) =-2529a(17) =3671a(18) =-406a(19) =-8323a(20) =16071a(21) =-8560a(22) =-24157a(23) =64859a(24) =-57822a(25) =-55351a(26) =242891a(27) =-303184a(28) =-50409a(29) =839375