Use Table 4.170 to compute the node number of the H4 node whose coordinates are (13, 6). The second approach to Hilbert curve traversal uses Table Ans.43. Orientation #2 of the H2 curve shown in Figure 4.162(b) is traversed in order 1223. The same orientation of the H3 curve of Figure 4.162(c) is traversed in 2114 1223 1223 4332, but Table Ans.43 tells us that 2114 is the traversal order for orientation #1 of H2, 1223 is the traversal for orientation #2 of H2, and 4332 is for orientation #3. The traversal of orientation #2 of H3 is therefore also based on the sequence 1223. Similarly, orientation #2 of H4 is traversed (Figure 4.163) in the order
1223 2114 2114 3441 2114 1223 1223 4332
2114 1223 1223 4332 3441 4332 4332 1223,
which is reduced to 2114 1223 1223 4332, which in turn is reduced to the same sequence 1223.