When is sum of squares a perfect square?
22840
The sum of the first $n$ squares is a square: a system of two Pell-type-equations
18402
Sum of the reciprocals of divisors of a perfect number is $2$?
101835
Which rationals can be written as the sum of two rational squares?
154082
Product of factorials divided by factorial to produce perfect square
48787
A number is a perfect square if and only if it has odd number of positive divisors
16472
Sum of First $n$ Squares Equals $\frac{n(n+1)(2n+1)}{6}$
134
Prove that the expression is a perfect square
50615
Expressing a Non Negative Integer as Sums of Two Squares
130499
How can $p^{q+1}+q^{p+1}$ be a perfect square?
63383
Integers $n$ for which $|2^n + 5^n – 65|$ is a perfect square
55206
Prove that the equation $x^4+(2k^2)x^2+2k^4$ is not a perfect square
72437
Sum of the digits of a perfect square
134121
Determining all the positive integers $n$ such that $n^4+n^3+n^2+n+1$ is a perfect square.
79103
Check if a number is a perfect square
138548
For what pair of integers $(a,b)$ is $3^a + 7^b$ a perfect square.
19588
$n!+1$ being a perfect square
46606
Can an integer of the form $4n+3$ written as a sum of two squares?