a(n) = 31 - n.

Terms

a(0) =31a(1) =30a(2) =29a(3) =28a(4) =27a(5) =26a(6) =25a(7) =24a(8) =23a(9) =22a(10) =21a(11) =20a(12) =19a(13) =18a(14) =17a(15) =16a(16) =15a(17) =14a(18) =13a(19) =12a(20) =11a(21) =10a(22) =9a(23) =8a(24) =7a(25) =6a(26) =5a(27) =4a(28) =3a(29) =2