function y=descendants(ij)
load indices
if ij>64 & ij<257
y=indices(ij,:);
y1=indices(indices(ij,:),:);
y1=y1';
y2=indices(indices(indices(ij,:),:),:);
y2=y2';
y=[y y1(:)' y2(:)'];
elseif ij>256 & ij<1025
y=indices(ij,:);
y1=indices(indices(ij,:),:);
y1=y1';
y=[y y1(:)'];
elseif ij>1024 & ij<4097
y=indices(ij,:);
else
y=[];
end