Polyhexes with holes: A038144 and A057210

[Ralf Stephan]

Sorry but: perhaps this one should be counted in A057210 but not in A038144?
Unfortunately, with n=10 this would make the last entry different!

Take naphtene and put at every C a hex:

                  +---+       +---+
                 /     \     /     \
            +---+       +---+       +---+
           /     \     /     \     /     \
          +       +---+       +---+       +
           \     /     \     /     \     /
            +---+ empty +---+ empty +---+
           /     \     /     \     /     \
          +       +---+       +---+       +
           \     /     \     /     \     /
            +---+       +---+       +---+
                 \     /     \     /
                  +---+       +---+

So, two holes but you cannot say it's a ring!


ralf