Similar to バーンサイド問題

Andrica's conjecture

Erdős–Straus conjecture

Collatz conjecture

Conway's 99-graph problem

Smale's problems

Moving sofa problem

List of unsolved problems in statistics

Navier–Stokes existence and smoothness

Pierce–Birkhoff conjecture

Beal conjecture

Hilbert's problems

Fermat–Catalan conjecture

Kobon triangle problem

Farrell–Jones conjecture

Hodge conjecture

Millennium Prize Problems

Yang–Mills existence and mass gap

Riemann hypothesis

Lychrel number

Class number problem

Ruth–Aaron pair

Mathematics

0.999...

Zero-dimensional space

Zero to the power of zero

One-dimensional space

1 + 1 + 1 + 1 + ⋯