Rows of Pascal's triangle mod 3.

Terms

a(0) =1a(1) =11a(2) =121a(3) =1001a(4) =11011a(5) =121121a(6) =1002001a(7) =11022011a(8) =121212121a(9) =1000000001a(10) =11000000011a(11) =121000000121