diff --git a/README.md b/README.md
index 0fbd171..b802e65 100644
--- a/README.md
+++ b/README.md
@@ -28,7 +28,7 @@ Some programs are in Jupyter (`.ipynb`) notebooks, some in `.py` files. For each
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Sierpinski.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FSierpinski.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FSierpinski.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Sierpinski.ipynb) | <b><a href="ipynb/Sierpinski.ipynb" title="A surprising appearance of the Sierpinski triangle in a random walk between vertexes">Chaos with Triangles</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Life.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FLife.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FLife.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Life.ipynb) | <b><a href="ipynb/Life.ipynb" title="The cellular automata zero-player game">Conway's Game of Life</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Dice%20Baseball.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FDice%20Baseball.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FDice%20Baseball.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Dice%20Baseball.ipynb) | <b><a href="ipynb/Dice%20Baseball.ipynb" title="Simulating baseball games">Dice Baseball</a></b> |
-| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Maze.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FMaze.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FMaze.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Maze.ipynb) | <b><a href="ipynb/Maze.ipynb" title="Make a maze by generating a random tree superimposed on a grid">Generating Mazes</a></b> |
+| [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Maze.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FMaze.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FMaze.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Maze.ipynb) | <b><a href="ipynb/Maze.ipynb" title="Make a maze by generating a random tree superimposed on a grid; then solve it">Making and Solving Mazes</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Pickleball.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FPickleball.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FPickleball.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Pickleball.ipynb) | <b><a href="ipynb/Pickleball.ipynb" title="Scheduling a doubles tournament fairly and efficiently">Pickleball Tournament</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Project%20Euler%20Utils.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FProject%20Euler%20Utils.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FProject%20Euler%20Utils.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Project%20Euler%20Utils.ipynb) | <b><a href="ipynb/Project%20Euler%20Utils.ipynb" title="My utility functions for the Project Euler problems, including `Primes` and `Factors`">Project Euler Utilities</a></b> |
 | [co](https://colab.research.google.com/github/norvig/pytudes/blob/master/ipynb/Orderable%20Cards.ipynb) [dn](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fblob%2Fmaster%2Fipynb%2FOrderable%20Cards.ipynb)  [my](https://mybinder.org/v2/gh/norvig/pytudes/master?filepath=ipynb%2FOrderable%20Cards.ipynb) [nb](https://nbviewer.jupyter.org/github/norvig/pytudes/blob/master/ipynb/Orderable%20Cards.ipynb) | <b><a href="ipynb/Orderable%20Cards.ipynb" title="Can you get your hand of cards into a nice order with just one move?">Properly Ordered Card Hands</a></b> |