l(i,47−j)=l(i,47−ˆj)=1+q47−j×q47−ˆjqj×qˆj(ri210+l(i,j)−1)−ri210 .
(ii) For l(i,j)=l(i,ˆj) , for 1≤j≤23 but not for ˆj , then 24≤ˆj≤46 and qˆj=ri+210[l(i,j)−1]qj .