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Comments in green were written by me. Comments in blue were not written by me.
2020-01-02
It's interesting that the three puzzles with the most incorrect attempts can all be looked up on OEIS.
Day 15 -
https://oeis.org/A001055
- "number of ways of factoring n with all factors greater than 1"
Day 4 -
https://oeis.org/A001045
- "number of ways to tile a 2 × (n-1) rectangle with 1 × 2 dominoes and 2 × 2 squares"
Day 2 -
https://oeis.org/A002623
- "number of nondegenerate triangles that can be made from rods of length 1,2,3,4,...,n"
Adam Abrams
on
/blog/72
×1
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Happy 10+cos(τ) Approximation Day!
May 2020
A surprising fact about quadrilaterals
Interesting tautologies
Mar 2020
Log-scaled axes
Feb 2020
PhD thesis, chapter ∞
PhD thesis, chapter 5
PhD thesis, chapter 4
PhD thesis, chapter 3
Inverting a matrix
PhD thesis, chapter 2
Jan 2020
PhD thesis, chapter 1
Gaussian elimination
Matrix multiplication
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2019
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Dec 2019
Visualising MENACE's learning
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Christmas (2019) is coming!
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A non-converging LaTeX document
TMiP 2019 treasure punt
Jul 2019
Big Internet Math-Off stickers 2019
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Proving a conjecture
Apr 2019
Harriss and other spirals
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realhats
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2018
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Christmas cross stitch
MENACE in fiction
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Christmas (2018) is coming!
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Runge's Phenomenon
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World Cup stickers 2018, pt. 3
Mathsteroids
Jun 2018
World Cup stickers 2018, pt. 2
May 2018
A bad Puzzle for Today
Apr 2018
Building MENACEs for other games
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A 20,000-to-1 baby?
World Cup stickers 2018
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Origins of World War I
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Christmas (2017) is coming!
MENACE at Manchester Science Festival
Jun 2017
Big Ben Strikes Again
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The end of coins of constant width
Dragon curves II
Feb 2017
The importance of estimation error
Jan 2017
Is MEDUSA the new BODMAS?
2016
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Dec 2016
Christmas (2016) is over
Video game surfaces
Christmas card 2016
Nov 2016
Christmas (2016) is coming!
Oct 2016
Logical contradictions
Palindromic dates
Sep 2016
Tube map kaleidocycles
Jul 2016
Solving the cross diagonal cover problem
Jun 2016
Braiding, pt. 2
Braiding, pt. 1
Making names in Life
May 2016
Euro 2016 stickers
Mar 2016
Proving Pythagoras' theorem
Dragon curves
The
Mathematical Games
of Martin Gardner
Jan 2016
Christmas (2015) is over
2015
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Nov 2015
Christmas (2015) is coming!
Oct 2015
How to kick a conversion
How much will I win on the new National Lottery?
Aug 2015
How OEISbot works
MENACE
Mar 2015
Optimal Pac-Man
Tube map stellated rhombicuboctahedron
Logic bot, pt. 2
Design your own flexagon
Jan 2015
Tube map Platonic solids, pt. 3
2014
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Nov 2014
Logic bot
Sep 2014
Electromagnetic Field talk
Jun 2014
Tennis maths
May 2014
World Cup stickers
Apr 2014
Countdown probability, pt. 2
Countdown probability
Mar 2014
New machine unfriendly £1 coin, pt. 2
New machine unfriendly £1 coin
2013
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Dec 2013
Assorted christmaths
Pointless probability
Jul 2013
"Uncanny" royal coincidence
Raspberry Pi weather station
2012
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Nov 2012
Tube map Platonic solids, pt. 2
Oct 2012
Tube map Platonic solids
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weak imposition
signorini conditions
programming
trigonometry
world cup
determinants
captain scarlet
bubble bobble
coins
pizza cutting
anscombe's quartet
misleading statistics
finite element method
chess
preconditioning
a gamut of games
european cup
finite group
estimation
zines
sobolev spaces
hyperbolic surfaces
mathsjam
inverse matrices
pac-man
chalkdust magazine
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approximation
platonic solids
big internet math-off
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cambridge
game show probability
runge's phenomenon
dataset
arithmetic
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dragon curves
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pi approximation day
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hats
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phd
graph theory
tmip
nine men's morris
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numbers
quadrilaterals
electromagnetic field
Archive
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Friendly squares
2024
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Dec 2024
A regular expression Christmas puzzle
Christmas card 2024
Nov 2024
Christmas (2024) is coming!
Feb 2024
Zines, pt. 2
Jan 2024
Christmas (2023) is over
2023
▼ show ▼
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Dec 2023
Christmas card 2023
Nov 2023
Christmas (2023) is coming!
Zines
Sep 2023
TMiP 2023 puzzle hunt
May 2023
Chalkdust issue 17
Apr 2023
Logo Asteroids
Mar 2023
Mathsteroids on hyperbolic surfaces
Feb 2023
The databet
Jan 2023
Christmas (2022) is over
2022
▼ show ▼
▲ hide ▲
Dec 2022
Off-by-one errors
Christmas card 2022
Nov 2022
Christmas (2022) is coming!
Oct 2022
24 Hour Maths Game Show
Mar 2022
Approximating π
Feb 2022
Build your own MENACE
Jan 2022
Christmas (2021) is over
2021
▼ show ▼
▲ hide ▲
Dec 2021
Christmas card 2021
Nov 2021
Christmas (2021) is coming!
Sep 2021
TMiP 2021 puzzle hunt
May 2021
Close encounters of the second kind
Jan 2021
Christmas (2020) is over
2020
▼ show ▼
▲ hide ▲
Dec 2020
Christmas card 2020
Nov 2020
Christmas (2020) is coming!
Jul 2020
Happy 10+cos(τ) Approximation Day!
May 2020
A surprising fact about quadrilaterals
Interesting tautologies
Mar 2020
Log-scaled axes
Feb 2020
PhD thesis, chapter ∞
PhD thesis, chapter 5
PhD thesis, chapter 4
PhD thesis, chapter 3
Inverting a matrix
PhD thesis, chapter 2
Jan 2020
PhD thesis, chapter 1
Gaussian elimination
Matrix multiplication
Christmas (2019) is over
2019
▼ show ▼
▲ hide ▲
Dec 2019
Visualising MENACE's learning
Christmas card 2019
Nov 2019
Christmas (2019) is coming!
Sep 2019
A non-converging LaTeX document
TMiP 2019 treasure punt
Jul 2019
Big Internet Math-Off stickers 2019
Jun 2019
Proving a conjecture
Apr 2019
Harriss and other spirals
Mar 2019
realhats
Jan 2019
Christmas (2018) is over
2018
▼ show ▼
▲ hide ▲
Dec 2018
Christmas cross stitch
MENACE in fiction
Christmas card 2018
Nov 2018
Christmas (2018) is coming!
Sep 2018
Runge's Phenomenon
Jul 2018
World Cup stickers 2018, pt. 3
Mathsteroids
Jun 2018
World Cup stickers 2018, pt. 2
May 2018
A bad Puzzle for Today
Apr 2018
Building MENACEs for other games
Mar 2018
A 20,000-to-1 baby?
World Cup stickers 2018
Jan 2018
Origins of World War I
Christmas (2017) is over
2017
▼ show ▼
▲ hide ▲
Dec 2017
Christmas card 2017
Nov 2017
Christmas (2017) is coming!
MENACE at Manchester Science Festival
Jun 2017
Big Ben Strikes Again
Mar 2017
The end of coins of constant width
Dragon curves II
Feb 2017
The importance of estimation error
Jan 2017
Is MEDUSA the new BODMAS?
2016
▼ show ▼
▲ hide ▲
Dec 2016
Christmas (2016) is over
Video game surfaces
Christmas card 2016
Nov 2016
Christmas (2016) is coming!
Oct 2016
Logical contradictions
Palindromic dates
Sep 2016
Tube map kaleidocycles
Jul 2016
Solving the cross diagonal cover problem
Jun 2016
Braiding, pt. 2
Braiding, pt. 1
Making names in Life
May 2016
Euro 2016 stickers
Mar 2016
Proving Pythagoras' theorem
Dragon curves
The
Mathematical Games
of Martin Gardner
Jan 2016
Christmas (2015) is over
2015
▼ show ▼
▲ hide ▲
Nov 2015
Christmas (2015) is coming!
Oct 2015
How to kick a conversion
How much will I win on the new National Lottery?
Aug 2015
How OEISbot works
MENACE
Mar 2015
Optimal Pac-Man
Tube map stellated rhombicuboctahedron
Logic bot, pt. 2
Design your own flexagon
Jan 2015
Tube map Platonic solids, pt. 3
2014
▼ show ▼
▲ hide ▲
Nov 2014
Logic bot
Sep 2014
Electromagnetic Field talk
Jun 2014
Tennis maths
May 2014
World Cup stickers
Apr 2014
Countdown probability, pt. 2
Countdown probability
Mar 2014
New machine unfriendly £1 coin, pt. 2
New machine unfriendly £1 coin
2013
▼ show ▼
▲ hide ▲
Dec 2013
Assorted christmaths
Pointless probability
Jul 2013
"Uncanny" royal coincidence
Raspberry Pi weather station
2012
▼ show ▼
▲ hide ▲
Nov 2012
Tube map Platonic solids, pt. 2
Oct 2012
Tube map Platonic solids
Tags
christmas card
matrices
accuracy
noughts and crosses
books
graph theory
martin gardner
pi
a gamut of games
coins
latex
guest posts
asteroids
puzzles
national lottery
matrix of cofactors
captain scarlet
dataset
game show probability
manchester science festival
curvature
sorting
cambridge
gather town
folding paper
estimation
errors
wave scattering
phd
probability
royal institution
runge's phenomenon
bodmas
golden spiral
plastic ratio
advent calendar
chebyshev
manchester
standard deviation
zines
youtube
stirling numbers
pi approximation day
pythagoras
polynomials
statistics
weather station
stickers
interpolation
misleading statistics
palindromes
fonts
ternary
hats
graphs
sobolev spaces
programming
crochet
preconditioning
mathslogicbot
quadrilaterals
wool
talking maths in public
error bars
matrix of minors
approximation
propositional calculus
logic
video games
triangles
inverse matrices
matt parker
menace
databet
light
weak imposition
big internet math-off
newcastle
javascript
determinants
electromagnetic field
craft
draughts
hexapawn
turtles
platonic solids
gerry anderson
royal baby
world cup
boundary element methods
people maths
correlation
go
simultaneous equations
pizza cutting
chalkdust magazine
datasaurus dozen
ucl
friendly squares
frobel
recursion
chess
computational complexity
data
bots
cross stitch
python
pascal's triangle
inline code
matrix multiplication
folding tube maps
london underground
data visualisation
countdown
binary
dates
squares
exponential growth
london
crossnumber
finite element method
oeis
final fantasy
geometry
bempp
tmip
raspberry pi
logs
signorini conditions
regular expressions
edinburgh
dragon curves
php
map projections
mean
numbers
harriss spiral
machine learning
rugby
24 hour maths
realhats
games
rhombicuboctahedron
live stream
sound
kings
dinosaurs
gaussian elimination
convergence
sport
golden ratio
numerical analysis
reuleaux polygons
bubble bobble
flexagons
hannah fry
game of life
hyperbolic surfaces
logo
european cup
arithmetic
fence posts
the aperiodical
nine men's morris
news
mathsjam
radio 4
tennis
trigonometry
football
speed
anscombe's quartet
reddit
geogebra
pac-man
christmas
braiding
finite group
mathsteroids
fractals
© Matthew Scroggs 2012–2025
Day 15 - https://oeis.org/A001055 - "number of ways of factoring n with all factors greater than 1"
Day 4 - https://oeis.org/A001045 - "number of ways to tile a 2 × (n-1) rectangle with 1 × 2 dominoes and 2 × 2 squares"
Day 2 - https://oeis.org/A002623 - "number of nondegenerate triangles that can be made from rods of length 1,2,3,4,...,n"
on /blog/72