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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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Approximating π
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Build your own MENACE
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Christmas (2020) is coming!
Jul 2020
Happy -15+3τ-φ-√3 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
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Visualising MENACE's learning
Christmas card 2019
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Christmas (2019) is coming!
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A non-converging LaTeX document
TMiP 2019 treasure punt
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Big Internet Math-Off stickers 2019
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Proving a conjecture
Apr 2019
Harriss and other spirals
Mar 2019
realhats
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Christmas (2018) is over
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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
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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
Christmas (2017) is over
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Christmas card 2017
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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
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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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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
▼ 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
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craft
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football
warwick
noughts and crosses
kings
books
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chebyshev
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propositional calculus
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gaussian elimination
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hats
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hannah fry
christmas
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trigonometry
chess
zines
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friendly squares
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wool
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inline code
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cambridge
london underground
mean
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matrix of minors
tetris
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bluesky
big internet math-off
rhombicuboctahedron
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gerry anderson
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reuleaux polygons
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bodmas
alphabets
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matrix multiplication
folding paper
wordle
approximation
tmip
a gamut of games
sport
numbers
pi approximation day
sound
polynomials
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live stream
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manchester science festival
squares
crossnumber
thirteen
rugby
signorini conditions
mathsjam
the aperiodical
arithmetic
dates
php
pi
sobolev spaces
runge's phenomenon
draughts
error bars
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oeis
tennis
matrix of cofactors
misleading statistics
coventry
errors
nonograms
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phd
quadrilaterals
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inverse matrices
asteroids
golden spiral
reddit
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world cup
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frobel
simultaneous equations
radio 4
gather town
databet
light
logo
matrices
kenilworth
news
stirling numbers
national lottery
datasaurus dozen
nine men's morris
determinants
pythagoras
bubble bobble
bots
ucl
pokémon wordle
european cup
preconditioning
boundary element methods
fence posts
dragon curves
braiding
pizza cutting
logs
flexagons
guest posts
wave scattering
palindromes
pascal's triangle
edinburgh
Archive
Show me a random blog post
▼ show ▼
▲ hide ▲
2026
May 2026
World Cup stickers 2026
Apr 2026
A new puzzle every day
Mixing Wordle with other games
Feb 2026
Christmas (2025) is over
2025
Dec 2025
Christmas card 2025
Nov 2025
Christmas (2025) is coming!
Sep 2025
The partridge puzzle
Aug 2025
TMiP 2025 puzzle hunt
Jun 2025
A nonogram alphabet
Mar 2025
How to write a crossnumber
Jan 2025
Christmas (2024) is over
Friendly squares
2024
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 ▼
▲ hide ▲
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 -15+3τ-φ-√3 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
news
mathsteroids
realhats
cambridge
alphabets
kings
triangles
manchester science festival
dragon curves
matrices
inverse matrices
london underground
bubble bobble
databet
rust
crosswords
books
cross stitch
tennis
noughts and crosses
christmas
kenilworth
pi
manchester
ternary
rhombicuboctahedron
errors
pythagoras
chalkdust magazine
php
big internet math-off
bluesky
world cup
crossnumber
asteroids
light
misleading statistics
simultaneous equations
palindromes
stirling numbers
reddit
ucl
european cup
folding paper
final fantasy
trigonometry
london
curvature
people maths
signorini conditions
dinosaurs
statistics
bots
mathsjam
machine learning
correlation
pokémon
football
hannah fry
matt parker
hats
oeis
turtles
folding tube maps
flexagons
tmip
chebyshev
sport
probability
runge's phenomenon
gather town
game of life
data visualisation
estimation
zines
plastic ratio
phd
radio 4
rugby
pi approximation day
python
fractals
numerical analysis
christmas card
latex
inline code
geometry
polynomials
datasaurus dozen
royal baby
regular expressions
matrix of minors
hexapawn
wool
friendly squares
preconditioning
tetris
captain scarlet
stickers
boundary element methods
nonograms
bodmas
go
advent calendar
numbers
dataset
dates
national lottery
crochet
pac-man
countdown
gaussian elimination
finite group
mean
standard deviation
bempp
craft
matrix multiplication
pokémon wordle
golden spiral
the aperiodical
frobel
data
video games
24 hour maths
harriss spiral
logs
fonts
logo
wave scattering
game show probability
logic
golden ratio
edinburgh
pascal's triangle
chess
raspberry pi
recursion
anscombe's quartet
squares
nine men's morris
warwick
accuracy
matrix of cofactors
binary
live stream
wordle
platonic solids
electromagnetic field
gerry anderson
braiding
puzzles
approximation
weak imposition
programming
sound
arithmetic
hyperbolic surfaces
thirteen
geogebra
error bars
talking maths in public
a gamut of games
arrangement puzzles
fence posts
royal institution
martin gardner
menace
partridge puzzle
crossnumbers
interpolation
speed
graphs
quadrilaterals
weather station
newcastle
guest posts
pizza cutting
coventry
reuleaux polygons
coins
convergence
youtube
graph theory
map projections
propositional calculus
sorting
games
computational complexity
mathslogicbot
determinants
javascript
exponential growth
sobolev spaces
draughts
finite element method
© Matthew Scroggs 2012–2026
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