**Update (2005-12-09):** I recently learned that
Mark Owen (aka Quinapalus) has a website
where this puzzle, Interstice,
can be found, along with many other novel creations.
Highly recommended.

It is better to view his original version as I changed minor presentation details when I recorded it in my notes long ago. I'll keep this page around as a souvenir of one of the few times I've written nontrivial JavaScript code.

*p*<*q*<*r* are three-digit primes, fixed throughout.
All answer are to be written in base 10, unless otherwise stated.

Across | |
---|---|

0 | pqr |

8 | Sum of two squares, in base 8 |

9 | |

11 | 2 x 13A |

12 | Multiple of p |

13 | |

14 | Multiple of r |

15 | Prime, written in base 8 |

16 | p + q + r |

20 | |

22 | |

23 | 3D / 8 |

24 | |

25 | 24A^{2} + 2 |

26 | Square |

28 | Multiple of 81 |

29 | 3 x 0D - 2 |

Down | |
---|---|

0 | |

1 | 2 x 19D |

2 | 19D / 2 |

3 | |

4 | ^{3}√20A + √9A |

5 | |

6 | 2 x 17D |

7 | 2pqr |

10 | (Power of 2) + p |

12 | |

17 | Square |

18 | 1D + 2D |

19 | |

21 | |

27 | Composite |

From "Eureka", the journal of the Cambridge University Mathematical Society.

Long ago, Dr. David Paget sent me this puzzle. I have yet to encounter a number puzzle that is as satisfying to solve as this one.

__Click here to check your solution__