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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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Inverting a matrix
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PhD thesis, chapter 1
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The importance of estimation error
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Euro 2016 stickers
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Electromagnetic Field talk
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Tennis maths
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World Cup stickers
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Countdown probability, pt. 2
Countdown probability
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New machine unfriendly £1 coin, pt. 2
New machine unfriendly £1 coin
2013
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Assorted christmaths
Pointless probability
Jul 2013
"Uncanny" royal coincidence
Raspberry Pi weather station
2012
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Tube map Platonic solids, pt. 2
Oct 2012
Tube map Platonic solids
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databet
a gamut of games
bubble bobble
dates
quadrilaterals
pac-man
correlation
coins
probability
european cup
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runge's phenomenon
royal baby
people maths
martin gardner
weak imposition
oeis
matt parker
gather town
php
rust
zines
gaussian elimination
turtles
golden ratio
regular expressions
recursion
data
matrix of minors
palindromes
simultaneous equations
raspberry pi
crossnumber
statistics
phd
standard deviation
mean
flexagons
anscombe's quartet
youtube
javascript
harriss spiral
newcastle
approximation
game show probability
sorting
python
wool
plastic ratio
news
weather station
braiding
numerical analysis
latex
inline code
pizza cutting
noughts and crosses
guest posts
fractals
books
accuracy
national lottery
nonograms
edinburgh
propositional calculus
tmip
platonic solids
realhats
logs
stirling numbers
matrices
golden spiral
captain scarlet
crossnumbers
alphabets
radio 4
numbers
chess
nine men's morris
exponential growth
curvature
frobel
christmas card
warwick
errors
advent calendar
data visualisation
folding tube maps
coventry
games
bempp
draughts
cambridge
pascal's triangle
london underground
signorini conditions
binary
rhombicuboctahedron
dragon curves
datasaurus dozen
polynomials
mathsjam
misleading statistics
asteroids
electromagnetic field
interpolation
light
go
machine learning
crochet
dinosaurs
royal institution
hannah fry
christmas
wave scattering
fence posts
trigonometry
estimation
inverse matrices
reuleaux polygons
craft
bodmas
live stream
dataset
matrix of cofactors
map projections
world cup
talking maths in public
hyperbolic surfaces
geometry
football
preconditioning
manchester
sobolev spaces
squares
partridge puzzle
video games
arithmetic
big internet math-off
graphs
menace
boundary element methods
ucl
kenilworth
chebyshev
crosswords
sport
convergence
tennis
fonts
game of life
speed
finite element method
rugby
computational complexity
thirteen
mathslogicbot
ternary
24 hour maths
bots
triangles
matrix multiplication
logic
friendly squares
reddit
chalkdust magazine
error bars
kings
pi approximation day
pythagoras
folding paper
sound
graph theory
stickers
determinants
countdown
final fantasy
geogebra
logo
programming
the aperiodical
finite group
cross stitch
mathsteroids
gerry anderson
hats
london
puzzles
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pi
Archive
Show me a random blog post
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2026
Feb 2026
Christmas (2025) is over
2025
▼ show ▼
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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
▼ show ▼
▲ hide ▲
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 -2+g-π 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
cambridge
javascript
asteroids
manchester science festival
frobel
christmas
hats
correlation
signorini conditions
quadrilaterals
game of life
london underground
convergence
national lottery
matrices
friendly squares
turtles
rust
crossnumber
bodmas
bubble bobble
chess
gerry anderson
newcastle
golden ratio
go
reuleaux polygons
error bars
matt parker
kings
radio 4
logic
databet
ucl
simultaneous equations
european cup
recursion
nine men's morris
gaussian elimination
pi
video games
mathsteroids
christmas card
accuracy
weather station
tmip
royal institution
interpolation
bots
martin gardner
palindromes
numbers
chebyshev
stickers
matrix of cofactors
binary
sound
books
finite element method
guest posts
crossnumbers
final fantasy
geometry
machine learning
finite group
inverse matrices
pascal's triangle
warwick
mathsjam
estimation
wave scattering
pi approximation day
wool
plastic ratio
data visualisation
fonts
hexapawn
live stream
thirteen
fence posts
gather town
logo
sport
pizza cutting
propositional calculus
people maths
graph theory
mathslogicbot
folding tube maps
errors
hyperbolic surfaces
fractals
talking maths in public
dinosaurs
php
dataset
platonic solids
squares
rhombicuboctahedron
speed
python
determinants
world cup
electromagnetic field
phd
sobolev spaces
oeis
runge's phenomenon
statistics
royal baby
regular expressions
curvature
noughts and crosses
triangles
programming
arithmetic
folding paper
nonograms
anscombe's quartet
misleading statistics
sorting
realhats
puzzles
polynomials
reddit
the aperiodical
crochet
captain scarlet
map projections
approximation
edinburgh
news
cross stitch
data
datasaurus dozen
mean
graphs
london
matrix of minors
advent calendar
dragon curves
rugby
harriss spiral
games
game show probability
stirling numbers
youtube
chalkdust magazine
alphabets
boundary element methods
draughts
manchester
standard deviation
ternary
matrix multiplication
a gamut of games
braiding
inline code
trigonometry
probability
hannah fry
menace
weak imposition
preconditioning
pythagoras
computational complexity
latex
raspberry pi
coins
24 hour maths
bempp
countdown
geogebra
exponential growth
flexagons
numerical analysis
dates
football
coventry
crosswords
pac-man
big internet math-off
logs
zines
light
partridge puzzle
kenilworth
craft
tennis
golden spiral
© 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