New posts in Square Numbers

Find all pairs of positive integers $(a,b)$ such that $2^a+5^b$ is a perfect square.

When is $ 999\cdots$ a perfect square?

Elementary number theory problem about finding a square number with digits with certain properties

Is there/can there be a model-theoretic proof of this theorem of arithmetic ?

Classification of the positive integers not being the sum of four non-zero squares

Why is there a pattern to the last digits of square numbers?

A conjecture concerning the number of divisors and the sum of divisors.

Prove that a number composed of only $2n$ "1"s, minus another number composed of only $n$ "2"s, is a perfect square.

Does $x+\sqrt{x}$ ever round to a perfect square, given $x\in \mathbb{N}$?

Product of 2-digit numbers