Material added on Martin Gardner's Centerary
 My poem for the Wolfram Blog
For today’s magic show:
A century ago,
Martin Gardner was born in Oklahoma.
He philosophized for his diploma.
He wrote on Hex and TicTacToe.
The Icosian game and polyomino.
Flexagons from paper trim,
Samuel Loyd, the game of Nim.
Digital roots and Soma stairs,
mazes, logic, magic squares.
Squaring squares, the golden Phi.
Solved the spider and the fly.
Packing circles (with corrections),
ellipses, pi, and conic sections.
Wolfram Blog.
 More on Martin Gardner
 From the New York Times, The Guardian, BBC News, Randi.org, maa.org.
Material added 7 October 2014
 Vacation Over
 Time to get back to this. Will try to have at least three items a day for awhile as I plow through the backlog.
 OEIS turns 50
 Neil Sloane's OEIS turns 50. OEIS.org turns 50, and Alex Bellos writes it up in the Guardian as Neil Sloane: the man who loved only integer sequences. But that's not true, Neil loves lots of things, like lattices and sphere packings.
 Tetrapents
 George Sicherman: I have not found any 5x5 pentapent solutions, but we can use the 7 tetrapents to make two congruent 28pents, providing that we use one of the tetrapents in both figures. This figure is unique, but the tiling on the left is not.
 TheMetagrobologist Magazine
 TheMetagrobologist Magazine is a very snazzy only magazine devoted to puzzles.
 Covent Garden Floating Market
 A very nice illusion of a floating building.
 The mateinn problem of infinite chess is decidable
 The mateinn problem of infinite chess is decidable  a new paper at arXiv.org.
 Pangrammic Top Ten
 Eric Harshbarger notes that last weeks top ten movies made a pangram.
 Martin Gardner Centennial
 Martin Gardner's 100th birthday is a few weeks away. Scientific American starts off the celebration.
Material added 20 March 2014
 Pentahex Holes
 George Sicherman  This weekend Abaroth sent me the attached picture of the 22 pentahexes. It has 33 holes, and is symmetric too. According to Andrew Clarke's Poly Pages, the old record was 30 holes.
 Toshihiro Shirakawa Polyboxes
 Toshihiro Shirakawa has found a number of new polyboxes.

 Hamiltonian Circuit for Rubik's cube
 A Hamiltonian solution for Rubik's Cube is known.
 Seven, Eight, and Nine Touching Cylinders
 Peter V. Pikhitsa1 and Mansoo Choi have a new paper, Seven, eight, and nine mutually touching infinitely long straight round cylinders.
 INCOME TAX FORM LOGIC PUZZLE
 Mark J. P. Wolf (from my workinprogress book, 101 Enigmatic Puzzles)
Within the new Short Form 1, there is a loophole; with just the right amount of income, you don’t owe any tax at all. Find the one income amount that will result in zero tax owed when the tax form below is filled out. (docx answer)  Recent Anagrams
 Arlo Guthrie's The City of New Orleans = Steel light train confers "How are you?".
I Have No Mouth And I Must Scream = A dour time to humans vs. machine.
Captain America: The Winter Soldier = WARipedia historical reenactment.
American Institute of Bisexuality = Caution: extreme unsatisfiability.
Christopher Nolan films esoteric ~ technothriller for space mission.
WorstCase Scenario Handbook = Coordinate SeahawksBroncos.
Electrochemical fluorination = Lime in the coconut for all I care.
Blockbuster motion picture = Put trust in comic book rebel.
Money is the root of all evil = Some love the irony of it all.
Let's run it up the flagpole = Telling "put up for the sale."
Institutional researcher = "In the literature" narcosis.
"A Tribute to Heroes" = He's about to retire.
Hi, G. Washington! = How's it hanging?
Crimea votes to ~ act more soviet.
Interest group = Peers tutoring.  Heesch2 Polyomino
 Glenn Rhoads found the minimal Heesch 2 polyomino in his 2003 thesis "Planar Tilings and the Search for an Aperiodic Prototile". I haven't seen it elsewhere, so here's a picture:
 Minimal Superpermutations
 123412314231243121342132413214321 has all permutations of "1234", and is minimal. The shortest string for "12345" is unknown. These are called minimal superpermutations, and much harder to find than DeBruijn sequences.
 Oskar Interview
 An interview with Oskar is up, you can also head to Oskar's website, or Oskar's youtube channel.
 Vixelstar
 George Sicherman  Here is a little puzzle that I call the Vixelstar. Just put the pieces on the left together to make the starshaped figure on the right. You may flip pieces over. Also, these pages were all added recently to Polyform Curiosities: Zucca's Challenge Problem for Tetracubes, Pentacubes in a Box, Galvagni Figures & Reid Figures for Polycairos, Tetrahendec Oddities, PentoPentoTrominoes, PentoPentoTetrominoes, Quadruple Pentominoes, and Printable Polycairo Grid.
 Similar Pentomino Shapes
 Livio Zucca: Odette De Meulemeester, George Sicherman and I are trying minimal solutions for each Pentomino, such as the type in the picture.
 Paths Through a Square
 Take 12 points around a square, with points in the corners and 4 points on each side. Join up the points with 6 lines, with no lines connecting points on the same side. The correct answer is 200 ways to do it. If mirror symmetries are removed, then there are 121 ways to do it.
 Top cited Math Papers
 Here's a list of the top cited math papers of all time.
 Attractive Attractors
 I liked this gallery of chaotic attractors.
 The Gentle Art of Filling Space
 A new book about the tiling patterns of Robert Reid is available.
 How to Tie a Tie
 How to knot a tie  177,147 distinct tie knots.
 Weird Paper Sculptures
 By making a huge stack of accordionjoined paper and then chiseling a bust out of it, surprisingly flexible heads can be made.
 Longest Entertainment Assemble?
 Star Trek original cast  25 years.
Jack Benny and Eddie "Rochester" Anderson  28 years.
Cheech and Chong  33 years.
Carson and McMahon  34 years.
Tom Baker and Louise Jameson  36 years.
Burns and Allen  36 years.
Marx Brothers  54 years.
Eddy Christiani and Frans Poptie  64 years.  Modeling a Perfect Pool Break
 Modeling a perfect break in the game of pool with Mathematica.
 Frank Longo Themeless Crossword
 This crossword fill for Fireball by Frank Longa is quite amazing.
 Golly on Android
 The excellent cellular automata program Golly is now available as Golly on Android.
 Wordplay Blog
 The Wordplay Blog at the New York Times has many nice problems, such as the Princess problem.
 Temari Spheres
 A 92YearOld grandmother creates a spectacular collection of embroidered Temari Spheres.
 New Folding Record
 MIT's Infinite Corridor was used to make a new folding record, breaking Britney Gallivan's paper folding record. I got her mentioned in the Numb3rs episode Identity Crisis.
 No Four in a Plane
 There are 38 ways to pick 13 points from a 5x5x5 grid so that no four points are in a plane. There is a unique solution for 8 points from 3x3x3, and 232 solutions for 10 points from 4x4x4. What are solutions for 6x6x6 and up?
Site Goals
Martin Gardner celebrates math
puzzles and
Mathematical Recreations. This site aims to do the same. If you've made
a good, new math puzzle, send it to ed@mathpuzzle.com.
My mail address is Ed Pegg Jr, 1607 Park Haven, Champaign, IL 61820.
You can join my moderated recreational mathematics email list at http://groups.yahoo.com/group/mathpuzzle/. My facebook page is at Ed Pegg Jr.