How to prove that 4900 is the only perfect square pyramid number above 1?
22840
The sum of the first $n$ squares is a square: a system of two Pell-type-equations
41571
Prove that in a sequence of numbers $49 , 4489 , 444889 , 44448889\ldots$
7414
Prove that odd perfect square is congruent to $1$ modulo $8$
140939
Smallest Perfect Cube ending in 888
48787
A number is a perfect square if and only if it has odd number of positive divisors
44790
Find $n$ for which $\frac{n(n+1)}{2}$ is perfect square
52055
how to prove $437\,$ divides $18!+1$? (NBHM 2012)
106922
Find the height of a square "pyramid" *General Form*
142580
Prove that a perfect square is either a multiple of $4$ or of the form $4q+1$.
76977
Prove that $f(n)$ is the nearest integer to $\frac12(1+\sqrt2)^{n+1}$?
38498
Find all primes $p$ such that $(2^{p-1}-1)/p$ is a perfect square
33737
Does $1.0000000000\cdots 1$ with an infinite number of $0$ in it exist?
153123
Proving by induction $4^n  0$
44528
The only natural number $x$ for which $x+\sqrt{-2}$ is a cube in $\mathbb{Z}[\sqrt{-2}]$ is $x=5$
72666
Prime Numbers And Perfect Squares
47247
How do we prove the existence of uncountably many transcendental numbers?
48430
Prove the following sequence always results in a perfect square.