a(n) = 23-n.

Terms

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