a(n) = n-17.

Terms

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