Generalized nim sum n + n in base 11.

Terms

a(0) =0a(1) =2a(2) =4a(3) =6a(4) =8a(5) =10a(6) =1a(7) =3a(8) =5a(9) =7a(10) =9a(11) =22a(12) =24a(13) =26a(14) =28a(15) =30a(16) =32a(17) =23a(18) =25a(19) =27a(20) =29a(21) =31a(22) =44a(23) =46a(24) =48a(25) =50a(26) =52a(27) =54a(28) =45a(29) =47