Puzzles
• Tim"s world of puzzles
Site dedicated to the World Puzzle Championship. http://www.home.zonnet.nl/kostunix/
• Erich"s Puzzle Palace
Mirror Puzzles, Number Puzzles, Hex Loop Puzzles, Path Puzzles, Battleship Puzzles, Triangulation Puzzles, Grid Puzzles, Cris-Cross Puzzles, Chess-Num Puzzles, Weight Puzzles, Logic Puzzles, Equation Puzzles, Rolling Block Mazes, Square Puzzles, Numerical Jigsaw Puzzles, Distance Puzzles, Rectangle Puzzles, MathPuzzle.com Puzzles, Number Link Puzzles, Pentomino Puzzles http://www.stetson.edu/~efriedma/puzzle.html
• Sloane"s On-Line Encyclopedia of Integer Sequences
The best and most comprehensive site about sequences in the web. http://www.research.att.com/~njas/sequences/
• Shack"s Math Problems
by By Michael Shackleford, A.S.A.
Anyone with an appreciation of a good math problem should find something they like here, with problems ranging from basic math to differential equations. http://www.thewizardofodds.com/math/
• The Grey Labyrinth
In The Grey Labyrinth, there is at least one unsolved puzzle at all times, available below. See if you can deduce the answer for yourself before they post it. http://www.greylabyrinth.com/index.htm
• Thinks.com
The brain games, puzzles and pastimes website. Crosswords and crossword variants, anagrams, doublets, trivia, riddles, chess problems, math puzzles, logic puzzles, wordsearch puzzles ... http://thinks.com/puzzles/
• Cryptarithms on line
by Jorge A C B Soares.
This site is exclusively devoted to cryptarithms. http://www.geocities.com/Athens/Agora/2160/
• Puzzle Fun
by Rodolfo Kurchan
PUZZLE FUN is a bulletin edited by Rodolfo Kurchan (Buenos Aires - Argentina) about polyominoes and other puzzles. http://www.geocities.com/TimesSquare/Maze/1320/rodolfo/pfun.html
• The prime puzzles and problems connection
by Carlos Rivera
Problems and puzzles on prime numbers. http://www.primepuzzles.net
• Math Archive
by Kirill Safarov
Over 200 problems. Common sense, Physics, Numbers, Knigths and Knaves, Logic, Probability, Miscellaneous, Geometry, Solids in 3D and Very Hard. http://www.matharchive.com
• Math puzzle.com
Martin Gardner celebrated math puzzles and Mathematical Recreations. This site aims to do the same. The webmaster, Ed Pegg Jr, is a twenty year member of the National Puzzler"s League, and frequently contributes to the New York Times crossword, Games, and National Public Radio"s Sunday Puzzler. http://www.mathpuzzle.com/
• Trevor Wood Puzzles
A great site about wooden mechanical puzzles. http://www.puzzles.force9.co.uk/index.htm