$(2n)!+1$ is not a perfect square for $n > 2$?
19588
$n!+1$ being a perfect square
50596
$p_1p_2...p_n +1$ is not square for $p_k = k$'th prime
24820
Prove that if $n$ is a perfect square, then either $n \equiv 1 \pmod 4$, or $n \equiv 0 \pmod 4$.
26011
To show that $2$ | $x^{2n} - x^n$, $n \in \mathbb{Z^+}$ is the following adequate?
134121
Determining all the positive integers $n$ such that $n^4+n^3+n^2+n+1$ is a perfect square.
7894
Does it follow that $(n!)^n$ divide $(n^2)!$
20691
prove that $\frac{(2n)!}{(n!)^2}$ is even if $n$ is a positive integer
83248
Vieta Jumping: Related to IMO problem 6, 1988: If $ab + 1$ divides $a^2 + b^2$ then $ab + 1$ cannot be a perfect square.
152754
When is the sum of divisors a perfect square?
57250
Proving that the sum and difference of two squares (not equal to zero) can't both be squares.
48787
A number is a perfect square if and only if it has odd number of positive divisors
135458
When is a sum of consecutive squares equal to a square?
5257
Proving that $(3n)!$ is divisible by $n! \times (n + 1)! \times (n + 2)!$ if $n$ is greater than 2
147666
How to prove that either $2^{500} + 15$ or $2^{500} + 16$ isn't a perfect square?
135212
The square of an integer has form $3n$ or $3n+1$
79847
proving of inequality $(n!)^2 \leq n^n\cdot n!\leq (2n!)$, where $n\in \mathbb{N}$
109305
Non-existence of natural numbers such that $\sqrt{n} +\sqrt{n+1} <\sqrt{x} +\sqrt{y} <\sqrt{4n+2}$