Nimsum n + 3.

Terms

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