# What about $x^2 -1?$

$3^2- 1$ is not a prime number.

$4^2 -1$ is not a prime number.

$5^2-1$ is not a prime number.

$6^2 -1$ is not a prime number.

$7^2 -1$ is not a prime number.

$8^2 -1$ is not a prime number.

Is it true that $x^2 -1$ is never a prime number for all positive integers $x \gt 2$?

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