a(n) = 3-n.

Terms

a(0) =3a(1) =2a(2) =1a(3) =0a(4) =-1a(5) =-2a(6) =-3a(7) =-4a(8) =-5a(9) =-6a(10) =-7a(11) =-8a(12) =-9a(13) =-10a(14) =-11a(15) =-12a(16) =-13a(17) =-14a(18) =-15a(19) =-16a(20) =-17a(21) =-18a(22) =-19a(23) =-20a(24) =-21a(25) =-22a(26) =-23a(27) =-24a(28) =-25a(29) =-26