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
 2025 

Mar 2025

How to write a crossnumber

Jan 2025

Christmas (2024) is over
Friendly squares
 2024 
▼ show ▼
 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

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

Archive

Show me a random blog post
▼ show ▼
© Matthew Scroggs 2012–2025