[r-t] Easter challenge

[Alexander Holroyd]

Yes, this is one of the graphs here:
http://www.math.ubc.ca/~holroyd/schreier/
Specifically it is this one:
http://www.math.ubc.ca/~holroyd/schreier/graphs-ps/g13245-14523.ps

There are also lots of interesting (and tricky) asymmetric methods that 
give the extent in 2 courses to be got from this graph.  Red Square Hybrid 
Doubles is the only rung one.  The others can be seen here:
http://www.math.ubc.ca/~holroyd/tp/tplines3.pdf
http://www.math.ubc.ca/~holroyd/tp/tplines4.pdf

Ander


Philip Saddleton pabs at cantab.net
Sun Apr 12 21:42:44 BST 2009

This is a problem that is small enough to analyse in depth with pencil
and paper (as I did in my hotel room last night). I came up with the
following graph which allows me to find all symmetrical single-hunt
methods whose plain course is the extent.

1A - 1B - 1C
   | x  | x  |
2A - 2B - 2C
   | x  |    |
3A - 3B   3C
   | x  |    |
4A - 4B - 4C
   | x  | x  |
5A - 5B - 5C