Saddle-Node Pairs

In the $0,1$ notation, saddle node pairs of orbits are represented by symbol strings beginning with a 0, ending with a 1, whose penultimate (next to last) symbol is 0 or 1, depending on whether the orbit is a saddle or node. For example, the third period five orbit has symbol name $000\underline{1}1$. This describes both the saddle $00011$ and the node $00001$.