Questions tagged [recreational-mathematics]

Mathematics done just for fun, often disjoint from typical school mathematics curriculum. Also see the [puzzle] and [contest-math] tags.

4,283 questions
Filter by
Sorted by
Tagged with
46 views

Flatland and dimensions

Isn't flatland assuming that the 2d objects have sides because otherwise there's no way they can even see lines? Even further, how come their eyes exist on sides, when they only exist in the 2d ...
66 views

What's the minimum number of keystrokes needed to type n asterisks?

Suppose you're editing a plain txt file and need to input a line of $n$ asterisk characters. You could press the * key $n$ times (assuming you have a numpad with a dedicated * key) but there is ...
11 views

Show that the set of factors of 12 under divisibility form a lattice. [closed]

Show that the set of factors of 12 under divisibility form a lattice.
7 views

414 views

Classifying all numbers $n$ with the property that if $p$ is a prime, then $p \mid n \iff p-1 \mid n$

If a number $n$ has the property that if $p$ is a prime, then $p \mid n \iff p-1 \mid n$, we call $n$ a nice number for brevity. A recent question on MSE (edit: now deleted) asks to prove that $1806$ ...
309 views

What is the maximum “alive density” of cells in Conway's Game of Life when played on a torus?

I've read that Conway's Game of Life (CGOL) can have unbounded growth from a finite initial number of alive cells (e.g. a glider gun). However, if CGOL is played on a torus, space (the number of cells)...