Newbetuts

Proving that $x$ is an integer, if the differences between any two of $x^{1919}$, $x^{1960}$, and $x^{2100}$ are integers

Guessing the length of a playlist on "shuffle random?"

Guaranteed Checkmate with Rooks in High-Dimensional Chess

Rubik's Cube Not a Group?

For which number does multiplying it by 99 add a 1 to each end of its decimal representation?

A lily pad doubles in area every second. After one minute, it fills the pond. How long would it take to quarter fill the pond ?

How few $(42^\circ,60^\circ,78^\circ)$ triangles can an equilateral triangle be divided into?

shorter proof of generalized mediant inequality?

Cutting out a circle using circles

Social Golfer Problem - Quintets

When you inscribe a triangle in a circle in a triangle in a circle in a triangle ...

Can a Rubik's cube be mapped knowing only two sides?

Can this ant find its way back to the nest?

Guessing number of colors of beads in an urn

Is there (or can there be) a general algorithm to solve Rubik's cubes of any dimension?

Mathematical joke regarding three people leaving a house [closed]

Does my "Prime Factor Look-and-Say" sequence always end?

New posts in recreational-mathematics

Xmas Maths 2014

What's the closest approximation to $\pi$ using the digits $0-9$ only once?

Zero-avoiding integers

Proving that $x$ is an integer, if the differences between any two of $x^{1919}$, $x^{1960}$, and $x^{2100}$ are integers

Guessing the length of a playlist on "shuffle random?"

Guaranteed Checkmate with Rooks in High-Dimensional Chess

Rubik's Cube Not a Group?

For which number does multiplying it by 99 add a 1 to each end of its decimal representation?

A lily pad doubles in area every second. After one minute, it fills the pond. How long would it take to quarter fill the pond ?

How few $(42^\circ,60^\circ,78^\circ)$ triangles can an equilateral triangle be divided into?

shorter proof of generalized mediant inequality?

Cutting out a circle using circles

Social Golfer Problem - Quintets

When you inscribe a triangle in a circle in a triangle in a circle in a triangle ...

Can a Rubik's cube be mapped knowing only two sides?

Can this ant find its way back to the nest?

Guessing number of colors of beads in an urn

Is there (or can there be) a general algorithm to solve Rubik's cubes of any dimension?

Mathematical joke regarding three people leaving a house [closed]

Does my "Prime Factor Look-and-Say" sequence always end?