That's me in small.

List of publications and
CV

equal surnames in Germany

Address: Augustenburgstr. 14, D-60488 Frankfurt/Main, Germany

Where I am working for: LH Systems.

- Mathematical Problems - List of several open problems
- Stable sets - The most wanted problem

- Results in Tiling and Packing - polycube and polysphere packings
- Martin Gardner - Contents of his books.

Crossing the bridge | Animated |

- Crossing the bridge - with a lamp (Crossing the bridge (long))
- discrete optimization - and a C program

- Sum Product - The impossible Puzzle
- Logic Puzzle - How old are they?
- lias and truth tellers - who is the spy?
- power 10 - powers in first order logic, a Gödel problem
- Mastermind - Errate die Kombination (German)

- expectation - number of fixpoint of a random permutation
- Random cyclic polygons - expected number of points which contain the center
- expectation - number of occurences of a fixed pattern in a 0-1-matrix (Truchet-tile)
- Partition Probabilities - Probability of a Factor (CRUX 2000)
- Red Black Game - How Often Should You Beat Your Kids
- Occupation - Likelihood Approximation
- expectation - Problem collection using Linearity
- Waiting time - poisson process
- 3 Door - Monty Hall puzzle
- Birthday problems - generalization and approximation

- sequences - Sequence Puzzles
- missing number - unusual sequence puzzles
- Elevator sequence
- Triangle Counting - in an regular n-gon
- Triangle Counting - in a triangular grid
- Square Counting - in a square grid
- Sum of reciprocal Binomials
- mod-2 Pascal Triangle - rational generating function
- Domino Tilings - and rhombic tilings.
- Nikolaus - how many Euler paths? (Nikolaus German)
- Euler numbers - Kellogg's problem
- Counting F - read this sentence
- Trinomials - number of odd values
- Divisible strings - consecutive divisible strings (ruby program)
- Triangles - how many triangles can you see?

- Alphametics - and Cryptarithms and the pharmacist's code
- Cryptogram - letter substitutions
- Number Place - puzzles
- 3 Digits - puzzles
- Snap - the snap games (spoiler)
- koray's cypher - with hints (German)
- Logical square - what is the missing value?

- www.mathpuzzle.com - site of Ed Pegg Jr.
- Problem Corner Org - 20000 math problems
- Erich's Site - Math Magic, Packing Center
- www.puzzles.com - Serhiy Grabarchuk maintains a collection of traditional and original puzzles
- Nick's Mathematical Puzzles - Nick Hobson has a nice collection of mathematical puzzles
- Cut the Knot - interactive mathematics with Alex Bogomolny
- Polyomino Tilings - Micheal Reid's packings of like Polyomonoes
- Polyform Tilings - Andrew Clarke's wonderful site with good graphic and information
- Atlantis - Puzzles, Games and Art - Karl Scherer's site with chess and math puzzles
- Click Mazes - online mazes
- Logic Mazes - Abbott's page
- The Geometry Junkyard - mathematical oriented stuff by David Eppstein.
- Puzzles Archive - rec.puzzles (my local 1993 copy)

- Math 4 u - geometric and inequality problems (German)
- Jürgen Köller's Mathematische Basteleien - (English and German)

- Quantum - a math magazine (database) with a monthly contest problem
- Mathematics Magazine - a math magazine (database)
- Crux Mathematicorum - problems from mathematical olympiads
- Wurzel - a math. magazine for undergraduate students (German)
- Monoid - a math. magazine of the Univ. Mainz for young persons (German)

- Rope around the Earth - pull it tight
- Sunrise - Arnold's eureka
- Speed - Murder on the river
- Speed up - bicycle tour
- x^y = y^x - commuting powers
- Ladder - move a ladder around a corner
- Ladder and Box - ladder on the wall
- hinged Ladder - distance problem
- Define a Function - use min and max
- tripe vector product identity - fight for the best solution
- cube roots - which term is smaller?
- The Crease - Fold a sheet of paper
- 3,4,5 Triangle - halve it
- high percentages - percentage points (English/German)
- harmonic numbers - some questions
- tan sum - a trigonometric identity
- Ages - Who's Birthday?
- Approximation - by two constants
- Cogito: Der Heuhaufen - Wie lange reicht das Heu? (German)
- Alter - Wie alt ist Klaus? (German)

- Sturmian Words - characteristic of a real number
- Floor Sums - equations and inequalities
- Floor Equation - solving equations in real numbers
- Floor Cubed - Concrete Mathematics Club Casino
- Floor Recurrences - recurrences
- Floor Sequences - properties of these sequences
- Floor Integral - integration problems
- Operator - with floors

- Magic Hexagon - musings about magic hexagons.
- A Unique Magic Hexagon - Trigg's article
- arithmetic - puzzle, sum of consecutive numbers
- Square Problems - impossible squares
- N Card Monte - probability of picking a pair of the same color
- Engel Problem - integral (a^2+b^2) / (1+ab) are squares
- Prime Problem - proof :-)
- Impossible Polynomial - Diophatic
- 8 squares - Hurwitz equation and solution as ps-file or solution as pdf-file by H. Postl.
- Symmetric Diophatic - 3 vars
- 3 powers - Diophatic
- prime pattern - no universal pattern
- reducing to one digit - casting zeros

- Tails Up - turning 4 coins
- Contact Slide - slide 4 coins into the middle
- Sliding Pennies - Double contact moves
- Leolei - a sliding puzzles with L-pieces
- Peg Solitaire - the cross with different long arms
- Peg Solitaire - program
- Peg Solitaire - WWW Link
- Rubic Cube and beyond - for Cube Lovers (old short info)
- Jumping off of a swing - jump as far as you can

- Equilateral Triangle - six piece disscetion
- Pizza Theorem - dissceting a disc. Pizza Dissection with cinderella.
- 3 Square Covering - Minimal Cover of a Square
- Squares Covering a Square - total square area is fixed
- 3 Squares in a circle - a french toast puzzle
- isosceles triangles - a square dissection
- packing - the fridge
- Squares and a Circle - the circle always fits
- Circle in a long rectangle - 2n+1 circles (diameter 1) in a 2*n rectangle
- Four T Puzzle - fit them into a small square. Four T arrangments as a postscript file (8K, 13p)
- Strip Covering - Strip Cover of a Circle
- tilings - topologically equivalent. Solution to Collatz's tiling as a postscript file (111K, 12p). A survey paper of Olaf (in German) on this subject as postscript gzip file (345K, 17p) gives further references and more theory and pictures.
- Fault Free - domino tilings
- dissection - of rectangeles into two parts
- three like discs - a postscript file (1.7 K)
- Lege-Wege - A domino tiling game
- rep-tiles - L shape pieces
- Antislide - rigid domino rectangles
- Langford's Problem - 312132, 23421314 (Miller's Page)
- Wood Puzzles - Two impossible 4 piece puzzles

- Geometrical Paradox - Where does the hole come from
- Tetraedron Octahedron - some questions
- Trisection - of a line
- Views - reconstruct objects
- Match - some matchsticks
- Regeular Heptagon - four points on a circle
- Three Lines - contruct an equilateral triangle
- Steiner Lehmus - equal angle bisector and isosceles triangles
- van Aubel - squares on a quadrilateral
- circle intersection - a Helly property
- Egg Curves - how to draw eggs
- Spirals

- Magic Pencil - the buttonhole puzzles
- strange painting - hanging on two nails

- Gossip - how many phone calls? gossip solutions
- Waiting - for information (common sense information)
- three switches - finding the lost bit
- weighting - six weights 1, 2, 3, 4, 5, 6
- triple weighting - The Eleven Ball Puzzle

- IMO - official IMO site (links to national Mathematical Olympiads)
- Math Puzzle Competitions - John Scholes' IMO, Putnam, Swiss competitions
- Mathematik-Olympiaden e.V. - German mathematical competitions
- Quantum - a monthly math puzzle problem (with lovely animated pictures)
- The Art of Problem Solving - for eager math students
- Zahlenjagd - a monthly math puzzle problem (German). Very well done.

- Pentacube Contests - figures of old contests

- Cube 3 - No 3 on a line, No 4 on a plane
- Max Integer Set - no pair with distance 3
- Supper Problems - relative prime or division free
- Chain Links - to pay for room
- Some Sum Signs - matrix row and column sums
- Antimagic Matrices - made from -1, 0, 1
- Absolute Difference Triangles - Pool-Ball Tiangles
- Licence Plates - maximal number
- Crossless Matching - in the plane
- Condom Problem - Design
- Many Stars - Arrangement
- Brothers in Law - mutual relations
- Euler Tours - pathes in a grid
- Colored queens - Little queens puzzle
- Word Problem - a free group relation (polyomino)
- algorithm - cyclic word recognition

- group puzzle - xxx = 1 means xy = yx ?
- ring puzzle - xxx = x means xy = yx (Jacobson problem, a Herstein puzzle)

- Situation Puzzles - lateral thinking puzzles website www.lateralpuzzles.com
- Situation Puzzles - Jed's List of Situation Puzzles
- 5 Eier im Korb - wie geht das? (German)

- even * even = odd - how can that be?
- dot connection - with straight lines
- word play - word puzzles english and german
- geographicals - Some geographical math questions
- Mnemonics - of Pi
- Riddles - Brain Benders

- Algorithms in C or C++ to use
- Check Codes

- Twister - my fan page.
- String Figures - oder "anbändeln"

Torsten Sillke

Fakultät für Mathematik | Universität Bielefeld

last changed 2009-08-23