If $n$ is an odd integer, then $4\mid n^2 − 1$.
77816
Proof problem: Show that $n^2-1$ is divisible by $8$, if $n$ is an odd positive integer.
135614
Show that $2^n > n^2$ whenever n>4.
135351
$C(n,p)$: even or odd?
12967
Find all $n>1$ such that $\dfrac{2^n+1}{n^2}$ is an integer.
129680
Prove that $n$ is even.
52542
For which odd positive integer $n$ , is it true that $-1$ is not a positive power of $2$ modulo $n$?
52089
Group of $2n$ elements, $n$ odd, is not simple
114873
Show that if $n$ is not divisible by $2$ or by $3$, then $n^2-1$ is divisible by $24$.
103360
Prove $4p-3$ is a square knowing that $n\mid p-1$ and $p\mid n^3-1$, $p$ prime
95000
Using induction to prove that $2 \mid (n^2 − n)$ for $n\geq 1$
44182
Proving that an integer is even if and only if it is not odd
123267
Proving that even numbers equal the sum of two odd numbers.
6165
Proof by Induction $n^2+n$ is even
513
If n is an odd integer, show there exists a positive integer k such that 2^k mod n = 1.
148647
If $\dfrac{4x^2-1}{4x^2-y^2}$ is an integer, then it is $1$
48787
A number is a perfect square if and only if it has odd number of positive divisors
97411
If $x^n=y^n$ and $n$ is odd then $x=y$