That's the same as:
$$\begin{array}{ccccccccccccc}
O(3,3) &&&& O(4,2) &&&& O(5,1) &&&& O(6)\\\
&\nwarrow &&\nearrow &&\nwarrow &&\nearrow &&\nwarrow &&\nearrow &\\\
&& O(3,2) &&&& O(4,1) &&&& O(5) &&\\\
&\nearrow &&\nwarrow &&\nearrow &&\nwarrow &&\nearrow &&&\\\
O(2,2) &&&& O(3,1) &&&& O(4) &&&& \\\
&\nwarrow &&\nearrow &&\nwarrow &&\nearrow && && &\\\
&& O(2,1) &&&& O(3) &&&& &&\\\
&\nearrow &&\nwarrow &&\nearrow &&&& &&&\\\
O(1,1) &&&& O(2) &&&& &&&& \\
\end{array}$$