A050075 a(n)=|a(n-1)-a(m)|, where m=n-1-2^p and 2^p<n-1<=2^(p+1); 3 initial terms given.

1, 2, 3, 2, 0, 1, 1, 2, 0, 1, 1, 2, 0, 0, 1, 0, 2, 1, 1, 2, 0, 0, 1, 0, 2, 2, 1, 0, 2, 2, 2, 1, 1, 0, 2, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 2, 1, 0, 2, 2, 2, 1, 1, 1, 1, 0, 0, 2, 0, 2, 1, 0, 2, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 2, 1, 0, 2, 2, 2, 1, 1, 1