New posts in recreational-mathematics

What is the "fastest" increasing function that's useful in some area of math?

A variant of the Monty Hall problem

Function whose third derivative is itself.

Mathematics for the afterlife

Is there a nice proof that $123456789098765432111$ is prime?

Limit associated with a recursion

Can we find sums for $\int_1^{\infty }e^{\pi i t} \left(t^{1/t}-1\right) \, dt?$

Extending prime numbers digit by digit while retaining primality

How much weight is on each person in a human pyramid?

How many triangles

The expected outcome of a random game of chess?

Could the sum of an even number of distinct positive odd numbers be divisible by each of the odd numbers?

Expected number of people to not get shot?

"If $1/a + 1/b = 1 /c$ where $a, b, c$ are positive integers with no common factor, $(a + b)$ is the square of an integer"

Sharing a pepperoni pizza with your worst enemy

Multiplicative order of 2 mod p

What numbers can be created by $1-x^2$ and $x/2$?

How does the divisibility graphs work?

Xmas Maths 2015

What are some math books written in dialogue or story form, e.g., a teacher explaining to a student?