Nimsum n + 2.

Terms

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