Generalized nim sum n + n in base 6.

Terms

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