"An *étude* (a French word meaning *study*) is an instrumental musical composition, usually short, of considerable difficulty, and designed to provide practice material for perfecting a particular musical skill."—[Wikipedia](https://en.wikipedia.org/wiki/%C3%89tude)
('Advent of Code 2018',2018,'Advent-2018.ipynb','Puzzle site with a coding puzzle each day for Advent 2018 '),
('Advent of Code 2017',2017,'Advent%202017.ipynb','Puzzle site with a coding puzzle each day for Advent 2017'),
('Advent of Code 2016',2016,'Advent%20of%20Code.ipynb','Puzzle site with a coding puzzle each day for Advent 2016*'),
("Beal's Conjecture Revisited",2018,'Beal.ipynb',"A search for counterexamples to Beal's Conjecture"),
('Bike Speed Versus Grade',2020,'Bike%20Speed%20versus%20Grade.ipynb','How fast can I bike as the route gets steeper?'),
("Can't Stop",2018,'Cant-Stop.ipynb','Optimal play in a dice board game'),
('Chaos with Triangles',2019,'Sierpinski.ipynb','A surprising appearance of the Sierpinski triangle in a random walk between vertexes'),
("Conway's Game of Life",2017,'Life.ipynb','The cellular automata zero-player game'),
('Generating and Solving Mazes',2020,'Maze.ipynb','Make a maze by generating a random tree superimposed on a grid and solve it.'),
('Photo Focal Lengths',2020,'PhotoFocalLengths.ipynb','Generate charts of what focal lengths were used on a photo trip.'),
('Pickleball Tournament',2018,'Pickleball.ipynb','Scheduling a doubles tournament fairly and efficiently'),
('Project Euler Utilities',2017,'Project%20Euler%20Utils.ipynb','My utility functions for the Project Euler problems, including `Primes` and `Factors`'),
('Tracking Trump: Electoral Votes',2020,'Electoral%20Votes.ipynb','How many electoral votes would Trump get if he wins the state where he has positive net approval?'))}
{nbs('Logic and Number Puzzles',
('Cryptarithmetic',2014,'Cryptarithmetic.ipynb','Substitute digits for letters and make NUM + BER = PLAY'),
("Euler's Sum of Powers Conjecture",2018,"Euler's%20Conjecture.ipynb",'Solving a 200-year-old puzzle by finding integers that satisfy a<sup>5</sup> + b<sup>5</sup> + c<sup>5</sup> + d<sup>5</sup> = e<sup>5</sup>'),
('Four 4s, Five 5s, and Countdowns',2020,'Countdown.ipynb','Solving the equation 10 _ 9 _ 8 _ 7 _ 6 _ 5 _ 4 _ 3 _ 2 _ 1 = 2016. From an Alex Bellos puzzle'),
('Misanthropic Neighbors',2017,'Mean%20Misanthrope%20Density.ipynb','How crowded will this neighborhood be, if nobody wants to live next door to anyone else?'),
('Properly Ordered Card Hands',2018,'Orderable%20Cards.ipynb','Can you get your hand of cards into a nice order with just one move?'),
('Tour de 538',2020,'TourDe538.ipynb','Solve a puzzle involving the best pace for a bicycle race.'),
('Weighing Twelve Balls',2020,'TwelveBalls.ipynb','A puzzle where you are given some billiard balls and a balance scale, and asked to find the one ball that is heavier or lighter, in a limited number of weighings'),
('Equilength Numbers: FOUR = 4',2020,'equilength-numbers.ipynb','What number names have the same letter count as the number they name (such as FOUR)?'),
('Gesture Typing',2017,'Gesture%20Typing.ipynb','What word has the longest path on a gesture-typing smartphone keyboard?'),
('Ghost: A Word game',2017,'Ghost.ipynb','The word game Ghost (add letters, try to avoid making a word)'),
('How to Do Things with Words: NLP in Python',2018,'How%20to%20Do%20Things%20with%20Words.ipynb','Spelling Correction, Secret Codes, Word Segmentation, and more'),
("Let's Code About Bike Locks",2015,'Fred%20Buns.ipynb','A tale of a bicycle combination lock that uses letters instead of digits. Inspired by Bike Snob NYC'),
('Spelling Bee',2020,'SpellingBee.ipynb','Find the highest-scoring board for the NY Times Spelling Bee puzzle'),
('Translating English into Propositional Logic',2017,'PropositionalLogic.ipynb','Automatically convert informal English sentences into formal Propositional Logic'),
("World's Longest Palindrome",2017,'pal3.ipynb','Searching for a long Panama-style palindrome, this time letter-by-letter'),
("World's Shortest Portmantout Word",2020,'Portmantout.ipynb','Find a word that squishes together a bunch of words'),
('xkcd 1970: Name Dominoes',2018,'xkcd-Name-Dominoes.ipynb','Lay out dominoes legally; the dominoes have people names, not numbers'))}
('A Concrete Introduction to Probability',2018,'Probability.ipynb','Code and examples of the basic principles of Probability Theory'),
('Probability, Paradox, and the Reasonable Person Principle',2016,'ProbabilityParadox.ipynb','Some classic paradoxes in Probability Theory, and how to think about disagreements'),
('Estimating Probabilities with Simulations',2020,'ProbabilitySimulation.ipynb','When the sample space is too complex, simulations can estimate probabilities'),
('The Devil and the Coin Flip Game',2019,'Coin%20Flip.ipynb','How to beat the Devil at his own game'),
('The Unfinished Game .... of Risk',2020,"risk.ipynb","Determining who is likely to win an interminably long game of Risk"),
('WWW: Who Will Win (NBA Title)?',2019,'WWW.ipynb','Computing the probability of winning the NBA title, for my home town Warriors, or any other team'))}
{nbs('Computer Science Algorithms and Concepts',
('Bad Grade, Good Experience',2017,'Snobol.ipynb','As a student, did you ever get a bad grade on a programming assignment? (Snobol, Concordance)'),
('BASIC Interpreter',2017,'BASIC.ipynb','How to write an interpreter for the BASIC programming language'),
('How to Count Things',2020,'How%20To%20Count%20Things.ipynb','Combinatorial math: how to count how many things there are, when there are a lot of them'),
('Stable Matching Problem',2020,'StableMatching.ipynb','What is the best way to pair up two groups with each other, obeying preferences?'),
('Symbolic Algebra, Simplification, and Differentiation',2017,'Differentiation.ipynb','A computer algebra system that manipulates expressions, including symbolic differentiation'),
