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

Terms

a(0) =3a(1) =-1a(2) =-1a(3) =5a(4) =-5a(5) =-1a(6) =11a(7) =-15a(8) =3a(9) =23a(10) =-41a(11) =21a(12) =43a(13) =-105a(14) =83a(15) =65a(16) =-253a(17) =271a(18) =47a(19) =-571a(20) =795a(21) =-177a(22) =-1189a(23) =2161a(24) =-1149a(25) =-2201a(26) =5511a(27) =-4459a(28) =-3253a(29) =13223