When is the sum of the first $n$ squares a square?
22840
The sum of the first $n$ squares is a square: a system of two Pell-type-equations
18482
Can the squares with side $1/n$ be packed into a $1 \times \zeta(2)$ rectangle?
129755
Weighted sum of squares, in a finite field
69194
Partitioning sum of squares
50615
Expressing a Non Negative Integer as Sums of Two Squares
79677
Difference of squares - number of representations
132541
Showing ${1\over n}\sum|S_i|=O(\sqrt n)$ for $S_i\subset [n]$, $|S_i\cap S_i|\le 1$ for $i\ne j$
67968
When is $2^n -7$ a perfect square?
93948
Is my proof correct? $p_1p_2p_3\cdots p_n+1)$ cannot be the square of an integer
98440
Show that any non-negative rational integer may be written as the sum of two squares if it is of the form....
31318
Cardinality of cartesian square
144335
Sum of three numbers and the sum of their squares: $x^2+y^2+z^2 \geq \frac{1}{3}$ for $x+y+z=1$
55357
Why does drawing $\square$ mean the end of a proof?
59782
Are there any $n$ for which $ n^4+n^3+n^2+n+1$ is a perfect square?
77564
How to prove for each positive integer $n$, the sum of the first $n$ odd positive integers is $n^2$?
104494
$m$ doesn't come in the sequence $a_n=[n+\sqrt{n}+\frac{1}{2}]$ iff m is a perfect square
101835
Which rationals can be written as the sum of two rational squares?