a(n) = n-3.

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