a(n) is the number of integer tuples (x_1, x_2, ..., x_(k+1)) where 0 <= x_i <= b-1, such that |x_i - x_(i+1)| = d_i for all i, where (d_1, d_2, ..., d_k) are digits of n in base b.

Animation varies base b from 2 to 50 (grid size is b^2) and the mapping is (x,y) gets a(x xor y) mod 4 which is visualised by color.