New posts in recreational-mathematics

Longest path in a square grid

What is the flaw in this proof that all triangles are isosceles?

Is $11^2+12^2+13^2+14^2+15^2+16^2=1111$ special?

Why should Rubik's cube get attention from mathematicians?

Is high school contest math useful after high school?

Get $5$ by doing any operations with four $7$s

What is the smallest polyomino that can't surround a $1\times 1$ hole?

Is the Collatz conjecture in $\Sigma_1 / \Pi_1$?

Ways of choosing $16$ integers from first $150$ integers such that there is no $(a,b,c,d)$ for which $a+b=c+d$

Which week day(s) cannot be the first day of a century?

The next number that has this property?

Given an $n\times n\times n$ cube, what is the largest number of $1\times 1\times 1$ blocks that a plane can cut through?

Minimal generating set of Rubik's Cube group

What is the simplest ellipse that goes through exactly 13 lattice points?

Probability of $5$ fair coin flips having strictly more heads than $4$ fair coin flips

Shortest distance around a pyramid

How can I find integers which satisfy $\frac{150+n}{15+n}=m$?

Special properties of the number $146$

Non-self-intersecting "Robot Walks"

Infinite prisoners with hats -- is choice really needed?