A new puzzle every Saturday. Solutions one week later.

***Special invitation to the Collection-20***
In order to celebrate our 20th anniversary I will accept at least 20 new prime-puzzles, one per puzzler, to be published here starting the next May 26, after 10 more Saturdays.
I would expect these puzzles shine because of its novelty, ingenuity, difficulty or just beauty.
Please start sending your puzzle-proposal now on!

Puzzles received and accepted for the Collection-20: ten
 (up to 3/24/18).

1035 weeks, 1068 pages
19 years + 9 months +29 days
1035x7 = 7245 days since

Puzzle 918. Primes on the line y=x

The last five news

Date Puzzle about


March-23-18 Puzzle 917 Flavio Torasso
March-16-18 Puzzle 916 Emmanuel Vantieghem.
Mar-9-18 Puzzle 915

Puzzle 914

Puzzle 913

Jan van Delden and Emmanuel Vantieghem.

Dmitry Kamenetsky (adds better solutions)

Giovanni Resta

Mar-2-18 Puzzle 914 Emmanuel Vantieghem, Dmitry Kamenetsky
Feb-23-18 Puzzle 913

Puzzle 896

Jan van Delden and Carlos Rivera

Dmitry Kamenetsky


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These pages will be updated every Saturday morning -- Last Modified on: Friday, 23-Mar-2018 22:44:35 PDT

"Many thanks to Martha Rivera, Miguel H. Rivera and  G. L. Honaker, Jr. for reviewing and correcting the  very first version of these pages, dated on May 23, 1998 "

Copyright 1998-2012: Design by: LANDOIS