How do you prove that $n^2-1$ is composite when $n>2$?
126494
Prove that there doesn't exist any integer $x \ge 3$ such that $x^2-1$ is prime.
65466
How to prove this Fibonacci sequence statement: $F^2_{n+1} - F^2_{n-1} = F_{2n}$
65757
Prove that $n! + k$ is a composite number
130093
Prove by Induction : $n < 2^n$
10604
Prove $3^n > n^2$ by induction
80148
Prove $\gcd(a+b,a^2+b^2)$ is $1$ or $2$ if $\gcd(a,b) = 1$
133017
Prove that $n^n>1\times3\times5\times7\times \dots\times(2n-1)$
6165
Proof by Induction $n^2+n$ is even
152299
Proving $a^{n-1} \equiv 1 \mod n $ when n is not prime.
46102
Prove that $2^n +1$ in never a perfect cube
132089
How do I prove/disprove that $F_n^2 + F_{n\pm 1}^2 = F_{2n\pm 1}$, where $F_n$ is the $n$th Fibonacci number?
17047
Prove that if n is even then $n^2$ is even and if n is odd then $n^2$ is odd?
11867
Prove by induction that $n < 2^n$ for all $n \ge 1$
86479
How to Prove with Mathematical Induction $3^n > n^2$
143543
Prove that $(n - 1)^2 \mid n^k -1$ if and only if $(n - 1) \mid k$
100558
Prove that for any even positive integer $n$, $n^2-1 \mid 2^{n!}-1$
9217
Find $n$ such that $x^2 + x + 1$ is a factor of $(x+1)^n - x^n - 1$.