A new puzzle every Saturday. Solutions one week later.

>>>>Basic Stats<<<<
Oct.-31-2026
1484 weeks, 1515 pages & 10388 days
28 years 5 Months 8 days
Since May 23 1998

Puzzle of the week

Puzzle 1287 Ties Between the Final Digits of Primes

Curios by CR in Prime Curios!

(updated on April 30, 2021)

Latest ten news

No.

Date Puzzles about

Contributors

10 Oct-30-26 Puzzle 1286
Conjecture 113
Conjecture 114
Puzzle 1284
Csrlos Rivera, Gennady Gusev
Carlos Rivera
Tesfamichael Bogale
Gennady Gusev
9 Oct-23-26 Puzzle 1285




Puzzle 1284
Michael Branicky, Giorgios Kalogeropoulos, Gennady Gusev, Oscar Volpatti, Carlos RIvera, Jeff Heleen

Michael Branicky, Giorgios Kalogeropoulos, Gennady Gusev, Carlos Rivera, Oscar Volpatti
8 Oct-16-26 Puzzle 1284


Puzzle 1278

Links, Number 12,
section
"Matematical web
tools"
Michael Branicky, Jeff Heleen, Gennady Gusev

Roberto Angelone

An Absolute Primality Calculator for numbers of eight algebraic forms, by Carlos Rivera. (New! October 17, 2026)
7 Oct-9-26 Puzzle 1283




Puzzle 232

Problem 29
Jeff Heleen, Michael Branicky, Giorgos Kalogeropoulos, Emmanuel Vantieghem, Gennady Gusev, V. F. Izquierdo

Carlos Rivera

Carlos Rivera
6 Oct-2-26 Puzzle 1278

Puzzle 897
Puzzle 899
Roberto Angelone

Tatsuru Watanabe
Tatsuru Watanabe
5 Sep.-25-25 Puzzle 1282

Links & Puzzle 1279
Michael Branicky

C. Rivera has updated his Covering Sets Calculador
4 Sep.-11-26 Conjecture 113

Puzzle 71
Alain Rochelli

Diego González Gauss
3 Sep.-4-26 Puzzle 1281  Rahid Zaman, Michael Branicky, Giorgos Kalogeropoulos, Paul Cleary, Michael Hürter
2 Aug-28-26 See The Links page.



Puzzle
Coll20th-20


Problem 92
C. Rivera updates his two Calculators online:
CS Calculator V8 and 3NCS2.

Giorgos Kalogeropoulos/Rahid Zaman

Eric Brier
1 Aug-21-26 Puzle 1279 Arkadiusz Wesoloski, Carlos Rivera

 


These pages will be updated every Saturday morning -- Last Modified on: Friday, 30-Oct-2026 15:37:21 MST

"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