What numbers can be written as a sum of two odd squares?
138081
How to determine whether a number can be written as a sum of two squares?
63895
What is the next perfect square of the form 14444... in decimal notation?
38018
Arrangement of integers in a row such that the sum of every two adjacent numbers is a perfect square.
85272
$3x + 1$ is even iff $5x-2$ is odd
147562
Sum of squares diophantine equation
853
Write down the sum of sum of  sum of digits of $4444^{4444}$
101573
Subtracting even and odd binomial coefficients?
63774
If a and b are odd integers, then $8\mid (a^2-b^2)$
151508
How to determine number with same amount of odd and even divisors
125401
Mathematical Induction: Sum of first n odd perfect cubes
18402
Sum of the reciprocals of divisors of a perfect number is $2$?
45392
Every natural number can be written as the sum of distinct Fibonacci numbers?
123267
Proving that even numbers equal the sum of two odd numbers.
18461
Sum of odd Fibonacci Numbers
91951
How do I check if an integer is even or odd?
127566
$2AB$ is a perfect square and $A+B$ is not a perfect square
72389
Positive integer $n$ such that $2n+1$ , $3n+1$ are both perfect squares