mscroggs.co.uk
mscroggs.co.uk

subscribe

Comment

Comments

Comments in green were written by me. Comments in blue were not written by me.
I would appreciate a hint for puzzle 23. I am struggling to derive a recurrence relation or formula. How to find the pattern for number of ways?
Reza
on /blog/107
×1   ×1   ×1   ×1   ×1   
@Reza:

I didn't use a recurrence. When dividing into three areas, one of the the lines must span the entire grid creating two areas. Then one more line is used to split one of the just created areas into three areas. I just figured out how many ways there are to place the first line, then how many ways there are to place the second. There are two main scenarios you need to deal with:
1) Two horizontal or vertical lines
2) One horizontal and one vertical line

Hope that helps
Aaron
on /blog/107
×4   ×1   ×2   ×2   ×2   
@Aaron: Wow thank you Aaron, that was just the idea I needed. Very fun.
Reza
on /blog/107
×3   ×3   ×3   ×3   ×3   

Archive

Show me a random blog post
 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 ▼
 2022 
▼ show ▼
 2021 
▼ show ▼
 2020 
▼ show ▼
 2019 
▼ show ▼
 2018 
▼ show ▼
 2017 
▼ show ▼
 2016 
▼ show ▼
 2015 
▼ show ▼
 2014 
▼ show ▼
 2013 
▼ show ▼
 2012 
▼ show ▼

Tags

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

Archive

Show me a random blog post
▼ show ▼
© Matthew Scroggs 2012–2026