a(n) = 2 - n.

Terms

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