numberphiles's square-sum problem
27427
Arranging numbers from $1$ to $n$ such that the sum of every two adjacent numbers is a perfect power
114164
Square-free Integers Factorization
94060
Sum of square binomial coefficients
34617
Number Theory: which primes are a sum of two squares?
112644
The product of two numbers that can be written as the sum of two squares
81267
A simple doubt in number theory problem.
107964
Simple combinatorics problem.
66216
Squares, Cubes and Prime numbers
140433
The number of ways of writing an integer as a sum of two squares
104309
Pigeon-Hole Principle Common Sum
103347
combinatorial proof of summation
7785
Cardinality of sum-set
101832
Proof that sum of first $n$ cubes is always a perfect square
75023
A finite sum of prime reciprocals
67899
Integer squares of the form $x^4+x^3+x^2+x+1$
130851
Squaring the plane, with consecutive integer squares. And a related arrangement
135458
When is a sum of consecutive squares equal to a square?