a(n) = Nimsum n + 5.

Terms

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